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Technology Short Take #31

Monday, April 8, 2013 in Macintosh, Networking, Security, Storage, Virtualization by slowe | 3 comments

Welcome to Technology Short Take #31, my irregularly published series that takes a look at links, posts, articles, and thoughts from around the web related to core data center technologies. I hope that you find something useful!

Networking

  • Umair Hoodbhoy speculates in this post that the inclusion of Cisco’s ONE Controller in the recently-announced “Daylight” effort could mean the end for Big Switch’s Floodlight. (Umair’s play on words—”in Daylight there is no need for Floodlights”—is cute.)
  • Of course, Big Switch recently moved to “diversify,” if you will, away from just Floodlight with the introduction of Switch Light. As usual, Brent Salisbury has an excellent write-up on Switch Light, so I recommend reading his post. Switch Light seems like a good idea—more competition is always good, isn’t that what people say?—but I wonder how much cooperation Big Switch will get from the major networking vendors with regards to OpenFlow interoperability now that Big Switch is competing even more directly with them via Switch Light.
  • I think I might have mentioned this before (sorry if so), but here’s a good write-up on using the Edge Gateway CLI for monitoring and troubleshooting. Nice.
  • Greg Ferro examines a potential SDN use case (an OpenFlow use case) in the form of enterprise firewall migrations.
  • Just getting started in the networking field? Last year, Brent Salisbury put together a couple of great posts that help “refresh the basics” of networking. Part 1 covers Ethernet, IP, and TCP headers in Wireshark captures; part 2 pulls that together to show how the headers encapsulate in the OSI stack. If you’re not already familiar with this information, this is good reading.

Servers/Hardware

Nothing this time around, but I’ll stay alert for information I can include in the next Technology Short Take!

Security

  • Mounting guest disk images on the host? That’s a no-no from a security perspective—see here to learn why.
  • Mike Foley shared recently that the release candidate of the vSphere 5 Security Hardening Guide has been released. Check it out here.

Cloud Computing/Cloud Management

  • I haven’t had the chance to actually try it out myself, but Blueprint looks interesting. As the website describes it, it’s designed to “reverse engineer” servers so that you can migrate them into a configuration management system like Chef or Puppet.
  • Looking for a decent high-level overview of OpenStack and how it works? Check out this article titled “In a nutshell: How OpenStack works”. (As an aside, I think it’s awesome how Ken Pepple’s diagrams show up in all sorts of places. One day I hope my material proves as useful to folks.)
  • If you use Puppet for configuration management and want to deploy GlusterFS, be sure to check out this Puppet Forge module. I’ve tested it and it works as advertised.
  • This is an older article (published in May of last year), and it’s a bit on the lengthy side, but I like the tack the author uses. He describes cloud as the synthesis of many different forms of innovation within IT, pulling together things like open source, virtualization, distributed programming, NoSQL, DevOps/NoOps, distributed teams, dynamic languages, and Big Data (among others). He then goes on to provide examples of how organizations building or leveraging clouds are synthesizing these various independent technological innovations together. If you have a few minutes (as I said, it’s a bit on the lengthy side), I’d recommend reading it.

Operating Systems/Applications

  • This series is a bit older, but an interesting one nevertheless. Brian McClain, who was one of the presenters in a Cloud Foundry/BOSH session I liveblogged at VMworld 2012, has his own personal blog and posted a series of articles on using BOSH with vSphere. I hadn’t really considered how one might use BOSH for deploying (and managing) multi-VM applications on vSphere, but Brian provides some practical examples. Part 1 of the series is here, followed by part 2, part 3, part 4, and part 5.
  • Like using Markdown on OS X? You might find these handy.
  • Ah, the good old days of DOS…reborn as FreeDOS.
  • Go ahead, read up on YAML. You know you want to. Well, YAML is used in both Hiera (can be used with Puppet) and BOSH, after all.
  • Here’s another interesting tool that I haven’t had the opportunity to actually test myself. Oz looks like it could be quite useful—especially in virtualized/cloud computing environments—but I’m struggling to determine why I should use Oz instead of OS-specific mechanisms (like a kickstart file). If anyone has used Oz and can shed some light on this question, I’d appreciate it.
  • You may have heard that I recently switched from TextMate to BBEdit as my default OS X text editor (and therefore the tool whereby I do most of my content generation). As part of the switch, I found this to be helpful. (I might post a separate entry about the switch, if enough people seem interested in reading about it.)

Storage

Virtualization

That’s it for this time. I have plenty more links I wanted to share, but I figured I’d better not let this post get any longer. As always, courteous comments are welcome, so I invite you to participate in the conversation by adding your thoughts below.

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Announcing VMware vSphere Design, 2nd Edition

Tuesday, March 19, 2013 in Virtualization by slowe | 17 comments

I’ve been phenomenally lucky to be involved in a number of book projects around VMware vSphere. I think that most people probably know me for the wildly popular Mastering VMware vSphere 4 and Mastering VMware vSphere 5 books (released at VMworld 2009 and VMworld EMEA 2011, respectively), but in late 2010/early 2011 I also had the opportunity to collaborate with Forbes Guthrie and Maish Saidel-Keesing on VMware vSphere Design. Even though that book hasn’t sold as many units as the Mastering books, it’s a work of which I’m equally proud. The topic of designing vSphere environments can be difficult to address, but I think we did a pretty good job.

Today I’m excited to announce that Forbes Guthrie and I–along with some support from Kendrick Coleman–have undertaken a revision of that book, to be released as VMware vSphere Design, 2nd Edition.

VMware vSphere Design, 2nd Edition

In addition to a new cover design (nice, huh?), this new version of the book has a new interior as well! The book has been thoroughly updated to include design topics and considerations for vSphere 4, vSphere 5, and vSphere 5.1. In addition to discussing design topics like management, storage, networking, and security, Kendrick contributed content around design considerations for vCloud Director. The updated and expanded content makes this a great resource for anyone who will be designing VMware vSphere environments.

For more information about the book, or to see a list of resellers for the book, visit the publisher’s page.

Thanks, and I think I speak for Forbes and Kendrick when I say that we hope this resource is useful to you!

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Technology Short Take #30

Tuesday, March 5, 2013 in General by slowe | 4 comments

Welcome to Technology Short Take #30. This Technology Short Take is a bit heavy on the networking side, but I suppose that’s understandable given my recent job change. Enjoy!

Networking

  • Ben Cherian, Chief Strategy Officer for Midokura, helps make a case for network virtualization. (Note: Midokura makes a network virtualization solution.) If you’re wondering about network virtualization and why there is a focus on it, this post might help shed some light. Given that it was written by a network virtualization vendor, it might seem a bit rah-rah, so keep that in mind.
  • Brent Salisbury has a fantastic series on OpenFlow. It’s so good I wish I’d written it. He starts out by discussing proactive vs. reactive flows, in which Brent explains that OpenFlow performance is less about OpenFlow and more about how flows are inserted into the hardware. Next, he tackles the concerns over the scale of flow-based forwarding in his post on coarse vs. fine flows. I love this quote from that article: “The second misnomer is, flow based forwarding does not scale. Bad designs are what do not scale.” Great statement! The third post in the series tackles what Brent calls hybrid SDN deployment strategies, and Brent provides some great design considerations for organizations looking to deploy an SDN solution. I’m looking forward to the fourth and final article in the series!
  • Also, if you’re looking for some additional context to the TCAM considerations that Brent discusses in his OpenFlow series, check out this Packet Pushers blog post on OpenFlow switching performance.
  • Another one from Brent, this time on Provider Bridging and Provider Backbone Bridging. Good explanation—it certainly helped me.
  • This article by Avi Chesla points out a potential security weakness in SDN, in the form of a DoS (Denial of Service) attack where many switching nodes request many flows from the central controller. It appears to me that this would only be an issue for networks using fine-grained, reactive flows. Am I wrong?
  • Scott Hogg has a nice list of 9 common Spanning Tree mistakes you shouldn’t make.
  • Schuberg Philis has a nice write-up of their CloudStack+NVP deployment here.

Servers/Hardware

  • Alex Galbraith recently posted a two-part series on what he calls the “NanoLab,” a home lab built on the Intel NUC (“Next Unit of Computing”). It’s a good read for those of you looking for some very quiet and very small home lab equipment, and Alex does a good job of providing all the details. Check out part 1 here and part 2 here.
  • At first, I thought this article was written from a sarcastic point of view, but it turns out that Kevin Houston’s post on 5 reasons why you may not want blade servers is the real deal. It’s nice to see someone who focuses on blade servers opening up about why they aren’t necessarily the best fit for all situations.

Security

  • Nick Buraglio has a good post on the potential impact of Arista’s new DANZ functionality on tap aggregation solutions in the security market. It will be interesting to see how this shapes up. BTW, Nick’s writing some pretty good content, so if you’re not subscribed to his blog I’d reconsider.

Cloud Computing/Cloud Management

  • Although this post is a bit older (it’s from September of last year), it’s still an interesting comparison of both OpenStack and CloudStack. Note that the author apparently works for Mirantis, which is a company that provides OpenStack consulting services. In spite of that fact, he manages to provide a reasonably balanced approach to comparing the two cloud management platforms. Both of them (I believe) have had releases since this time, so some of the points may not be valid any longer.
  • Are you a CloudStack fan? If so, you should probably check out this collection of links from Aaron Delp. Aaron’s focused a lot more on CloudStack now that he’s at Citrix, so he might be a good resource if that is your cloud management platform of choice.

Operating Systems/Applications

  • If you’re just now getting into the whole configuration management scene where tools like Puppet, Chef, and others play, you might find this article helpful. It walks through the difference between configuring a system imperatively and configuring a system declaratively (hint: Puppet, Chef, and others are declarative). It does presume a small bit of programming knowledge in the examples, but even as a non-programmer I found it useful.
  • Here’s a three-part series on beginning Puppet that you might find helpful as well (Part 1, Part 2, and Part 3).
  • If you’re a developer-type person, I would first ask why you’re reading my site, then I’d point you to this post on the AMQP, MQTT, and STOMP messaging protocols.

Storage

Virtualization

  • Although these posts are storage-related, the real focus is on how the storage stack is implemented in a virtualization solution, which is why I’m putting them in this section. Cormac Hogan has a series going titled “Pluggable Storage Architecture (PSA) Deep Dive” (part 1 here, part 2 here, part 3 here). If you want more PSA information, you’d be hard-pressed to find a better source. Well worth reading for VMware admins and architects.
  • Chris Colotti shares information on a little-known vSwitch advanced setting that helps resolve an issue with multicast traffic and NICs in promiscuous mode in this post.
  • Frank Denneman reminds everyone in this post that the concurrent vMotion limit only goes to 8 concurrent vMotions when vSphere detects the NIC speed at 10Gbps. Anything less causes the concurrent limit to remain at 4. For those of you using solutions like HP VirtualConnect or similar that allow you to slice and dice a 10Gb link into smaller links, this is a design consideration you’ll want to be sure to incorporate. Good post Frank!
  • Interested in some OpenStack inception? See here. How about some oVirt inception? See here. What’s that? Not familiar with oVirt? No problem—see here.
  • Windows Backup has native Hyper-V support in Windows Server 2012. That’s cool, but are you surprised? I’m not.
  • Red Hat and IBM put out a press release today on improved I/O performance with RHEL 6.4 and KVM. The press release claims that a single KVM guest on RHEL 6.4 can support up to 1.5 million IOPS. (Cue timer until next virtualization vendor ups the ante…)

I guess I should wrap things up now, even though I still have more articles that I’d love to share with readers. Perhaps a “mini-TST”…

In any event, courteous comments are always welcome, so feel free to speak up below. Thanks for reading and I hope you’ve found something useful!

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Technology Short Take #29

Monday, February 4, 2013 in Networking, Security, Storage, Virtualization by slowe | 6 comments

Welcome to Technology Short Take #29! This is another installation in my irregularly-published series of links, thoughts, rants, and raves across various data center-related fields of technology. As always, I hope you find something useful here.

Networking

  • Who out there has played around with Mininet yet? Looks like this is another tool I need to add to my toolbox as I continue to explore networking technologies like OpenFlow, Open vSwitch, and others.
  • William Lam has a recent post on some useful VXLAN commands found in ESXCLI with vSphere 5.1. I’m a CLI fan, so I like this sort of stuff.
  • I still have a lot to learn about OpenFlow and networking, but this article from June of last year (it appears to have been written by Ivan Pepelnjak) discusses some of the potential scalability concerns around early versions of the OpenFlow protocol. In particular, the use of OpenFlow to perform granular per-flow control when there are thousands (or maybe only hundreds) of flows presents a scalability challenge (for now, at least). In my mind, this isn’t an indictment of OpenFlow, but rather an indictment of the way that OpenFlow is being used. I think that’s the point Ivan tried to make as well—it’s the architecture and how OpenFlow is used that makes a difference. (Is that a reasonable summary, Ivan?)
  • Brad Hedlund (who will be my co-worker starting on 2/11) created a great explanation of network virtualization that clearly breaks down the components and explains their purpose and function. Great job, Brad.
  • One of the things I like about Open vSwitch (OVS) is that it is so incredibly versatile. Case in point: here’s a post on using OVS to connect LXC containers running on different hosts via GRE tunnels. Handy!

Servers/Hardware

  • Cisco UCS is pretty cool in that it makes automation of compute hardware easier through such abstractions as server profiles. Now, you can also automate UCS with Chef. I traded a few tweets with some Puppet folks, and they indicated they’re looking at this as well.
  • Speaking of Puppet and hardware, I also saw a mention on Twitter about a Puppet module that will manage the configuration of a NetApp filer. Does anyone have a URL with more information on that?
  • Continuing the thread on configuration management systems running on non-compute hardware (I suppose this shouldn’t be under the “Servers/Hardware” section any longer!), I also found references to running CFEngine on network apliances and running Chef on Arista switches. That’s kind of cool. What kind of coolness would result from even greater integration between an SDN controller and a declarative configuration management tool? Hmmm…

Security

  • Want full-disk encryption in Ubuntu, using AES-XTS-PLAIN64? Here’s a detailed write-up on how to do it.
  • In posts and talks I’ve given about personal productivity, I’ve spoken about the need to minimize “friction,” that unspoken drag that makes certain tasks or workflows more difficult and harder to adopt. Tal Klein has a great post on how friction comes into play with security as well.

Cloud Computing/Cloud Management

  • If you, like me, are constantly on the search for more quality information on OpenStack and its components, then you’ll probably find this post on getting Cinder up and running to be helpful. (I did, at least.)
  • Mirantis—recently the recipient of $10 million in funding from various sources—posted a write-up in late November 2012 on troubleshooting some DNS and DHCP service configuration issues in OpenStack Nova. The post is a bit specific to work Mirantis did in integrating an InfoBlox appliance into OpenStack, but might be useful in other situation as well.
  • I found this article on Packstack, a tool used to transform Fedora 17/18, CentOS 6, or RHEL 6 servers into a working OpenStack deployment (Folsom). It seems to me that lots of people understand that getting an OpenStack cloud up and running is a bit more difficult than it should be, and are therefore focusing efforts on making it easier.
  • DevStack is another proof point of the effort going into make it easier to get OpenStack up and running, although the focus for DevStack is on single-host development environments (typically virtual themselves). Here’s one write-up on DevStack; here’s another one by Cody Bunch, and yet another one by the inimitable Brent Salisbury.

Operating Systems/Applications

  • If you’re interested in learning Puppet, there are a great many resources out there; in fact, I’ve already mentioned many of them in previous posts. I recently came across these Example42 Puppet Tutorials. I haven’t had the chance to review them myself yet, but it looks like they might be a useful resource as well.
  • Speaking of Puppet, the puppet-lint tool is very handy for ensuring that your Puppet manifest syntax is correct and follows the style guidelines. The tool has recently been updated to help fix issues as well. Read here for more information.

Storage

  • Greg Schulz (aka StorageIO) has a couple of VMware storage tips posts you might find useful reading. Part 1 is here, part 2 is here. Enjoy!
  • Amar Kapadia suggests that adding LTFS to Swift might create an offering that could give AWS Glacier a real run for the money.
  • Gluster interests me. Perhaps it shouldn’t, but it does. For example, the idea of hosting VMs on Gluster (similar to the setup described here) seems quite interesting, and the work being done to integrate KVM/QEMU with Gluster also looks promising. If I can ever get my home lab into the right shape, I’m going to do some testing with this. Anyone done anything with Gluster?
  • Erik Smith has a very informative write-up on why FIP snooping is important when using FCoE.
  • Via this post on ten useful OpenStack Swift features, I found this page on how to build the “Swift All in One,” a useful VM for learning all about Swift.

Virtualization

  • There’s no GUI for it, but it’s kind of cool that you can indeed create VM anti-affinity rules in Hyper-V using PowerShell. This is another example of how Hyper-V continues to get more competent. Ignore Microsoft and Hyper-V at your own risk…
  • Frank Denneman takes a quick look at using user-defined NetIOC network resource pools to isolate and protect IP-based storage traffic from within the guest (i.e., using NFS or iSCSI from within the guest OS, not through the VMkernel). Naturally, this technique could be used to “protect” or “enhance” other types of important traffic flows to/from your guest OS instances as well.
  • Andre Leibovici has a brief write-up on the PowerShell module for the Nicira Network Virtualization Platform (NVP). Interesting stuff…
  • This write-up by Falko Timme on using BoxGrinder to create virtual appliances for KVM was interesting. I might have to take a look at BoxGrinder and see what it’s all about.
  • In case you hadn’t heard, OVF 2.0 has been announced/released by the DMTF. Winston Bumpus of VMware’s Office of the CTO has more information in this post. I also found the OVF 2.0 frequently asked questions (FAQs) to be helpful. Of course, the real question is how long it will be before vendors add support for OVF 2.0, and how extensive that support actually is.

And that’s it for this time around! Feel free to share your thoughts, suggestions, clarifications, or corrections in the comments below. I encourage your feedback, and thanks for reading.

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New Year, New Challenges, New Opportunities

Friday, January 25, 2013 in General, Networking, Virtualization by slowe | 33 comments

I suppose there’s no sense in beating around the bush. As the blog post title indicates, I’m taking on a new set of challenges (and a new set of opportunities) in 2013—and the way to do that is in a new role with a new company. So, effective 2/8/2013, I am leaving EMC Corporation to join the former Nicira group at VMware, working directly for Martin Casado. I’ll be working with folks like Brad Hedlund (see his announcement here), Bruce Davie, and Teemu Koponen. I’m truly awed by the talent on this team.

My time at EMC over the last three years has been great, and my choice to leave was a difficult choice to make. The decision to leave does not reflect anything bad about EMC, but rather reflects the magnitude of the opportunities for personal and professional growth that lie ahead with VMware’s virtual networking group. There is a saying among my former team at EMC that goes like this: “Once a vSpecialist, always a vSpecialist.” I don’t agree with this statement, because it implies a sense of permanence—something those of us in IT simply can’t afford to have. You must change, you must evolve, you must become something more than what you were in the past, or you will become irrelevant. While I appreciate my time at EMC—both my time as a vSpecialist and my time within the ESG CTO’s office—the time for growth and evolution has come. This move will help me further evolve and grow. I’ve always been interested in networking, but this will be the first time it will be the primary focus for me, and I’m really looking forward to expanding my knowledge, learning new concepts and ideas, and leveraging my existing experience and expertise with virtualization in new and exciting ways.

Although there are great opportunities ahead, there are also a few challenges. I’m not relocating (I love Denver too much!), but my travel schedule will ramp up quite a bit. Travel has been down for me for the last several months (since I left the vSpecialist team), but in the new role my travel will go back up again as I’ll be meeting with the rest of the virtual networking team in Palo Alto, meeting with strategic customers and partners, supporting community events (expect to see me at VMUG events), and educating field sales resources on virtual networking and why it’s important. Undoubtedly the increased travel will have an impact on Crystal and the rest of the family, and I appreciate everyone’s thoughts and prayers as we sort that out.

One other challenge will come from a shift in “allegiance.” I experienced a similar effect when I joined EMC. When I was with ePlus (it seems so long ago!) I was able to maintain reasonably good relationships with different storage vendors as well as different networking vendors. When I joined EMC, the other storage vendors no longer wanted to work with me. I suppose I can understand that. I was able, though, to continue maintain reasonably good relationship with various networking vendors (and even a few other virtualization vendors). I suspect now, though, that my shift to VMware will alter that landscape again. I can only hope the relationships I’ve established with colleagues at “competing” organizations (real or perceived competition) aren’t negatively affected too much.

Long-time readers know that several transitions have occurred over the nearly 8 years that I’ve been writing here. As I’ve done for the last 8 years, I’ll continue to post as much useful, relevant, and interesting content here as I’m able. Will there be a shift in focus? Possibly; I can’t promise there won’t be. Still, I’ll strive to keep sharing as much as I’m able as together we grow, change, and evolve along with the IT industry. Thanks for the support, and I hope that it continues.

Courteous comments are always welcome, so if you have questions or thoughts you want to share, feel free to speak up below.

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Using Mock to Build Libvirt 1.0.1 RPMs for CentOS 6.3

Tuesday, January 22, 2013 in Linux, Virtualization by slowe | No comments

In this third post on using Mock to build RPMs for CentOS 6.3, I’m going to show you how to use Mock to build RPMs for Libvirt 1.0.1 that you can install on CentOS. As you’ll see later, this post builds on the previous two posts (one on using Mock to build RPMs for sanlock 2.4 and one on using Mock to build RPMs for libssh2 1.4.1).

Here’s a quick overview of the process:

  1. Set up Mock and the environment.
  2. Install prerequisites into the Mock environment.
  3. Build the Libvirt RPMs.

Let’s take a closer look at each of these steps.

Setting Up Mock and the Environment

The first phase in the process is to set up Mock and the environment for building the RPMs. Fortunately, this is relatively simple.

First, activate EPEL. My preferred method for activating the EPEL repository is to download the RPM, then use yum localinstall to install it, like this:

wget http://fedora.mirrors.pair.com/epel/6/i386/\
epel-release-6-8.noarch.rpm
yum localinstall epel-release-6-8.noarch.rpm

(Note that I’ve line-wrapped the URL with a backslash to make it more readable. That line-wrapped command actually works just as it is in the shell as well.)

Next, you’ll need to install Mock and related RPM-building tools:

yum install fedora-packager

Third, create a dedicated user for building RPMs. I use “makerpm” as my username, but you could use something else. Just make sure that the name makes sense to you, and that the new user is a member of the mock group:

useradd makerpm -G mock
passwd makerpm

From this point on, you’ll want to be running as this user you just created, so switch to that user with su - makerpm. This ensures that the RPMs are built under this dedicated user account.

The final step in setting up Mock and the build environment is to run the following command while running as the dedicated user you created:

rpmdev-setuptree

Now you’re ready to move on to the next phase: installing prerequisites into the Mock environment.

Installing Prerequisites Into the Mock Environment

One of the great things about Mock is that it creates an isolated chroot into which it installs all the necessary prerequisites for a particular package. This helps ensure that the package’s dependencies are managed correctly. However, if you are trying to build a package where dependencies don’t exist in the repositories, then you have to take a few additional steps. When you’re trying to build libvirt 1.0.1 RPMs for use with CentOS 6.3, you’ll find yourself in exactly this situation. Libvirt has dependencies on newer versions of sanlock-devel and libssh2-devel than are available in the repositories.

Fortunately, there is a workaround—and here’s where those other posts on Mock will come in handy. Use the instructions posted here to build RPMs for sanlock 2.4, and use the instructions here to build RPMs for libssh2 1.4.1.

Once the RPMs are built (and they should build without any major issues, based on my testing), then use these commands to get them into the isolated Mock environment (I’ve line-wrapped here with backslashes for readability):

mock -r epel-6-x86_64 --init
mock -r epel-6-x86_64 --install \
~/rpmbuild/RPMS/sanlock-lib-2.4-3.el6.x86_64.rpm \
~/rpmbuild/RPM/sanlock-devel-2.4-3.el6.x86_64.rpm \
~/rpmbuild/RPMS/libssh2-1.4.1-2.el6.x86_64.rpm \
~/rpmbuild/RPMS/libssh2-devel-1.4.1-2.el6.x86_64.rpm

This will install these packages into the Mock environment, not onto the general Linux installation.

Once you’ve gotten these packages compiled and installed, then you’re ready for the final phase: building the libvirt RPMs.

Building the Libvirt RPMs

As in my earlier post on compiling Libvirt 1.0.1 RPMs for CentOS 6.3, this final step is almost anti-climactic. That’s good, though, because it means you’ve done all the previous steps perfectly.

First, fetch the source RPM from the libvirt HTTP server:

wget http://libvirt.org/sources/libvirt-1.0.1-1.fc17.src.rpm

Next, move the source RPM into the ~/rpmbuild/SRPMS directory:

mv libvirt-1.0.1-1.fc17.src.rpm ~/rpmbuild/SRPMS

Finally, run Mock to rebuild the RPMs:

mock -r epel-6-x86_64 --no_clean ~/rpmbuild/SRPMS/libvirt-1.0.1-1.fc17.src.rpm

Note that the --no-clean parameter is required here to prevent Mock from cleaning out the chroot and getting rid of the packages you installed into the environment earlier.

This command should run without any errors or problems, and produce a set of RPMs (typically) found in /var/lib/mock/epel-6-x86_64/results. You can then take these RPMs and install them on another CentOS 6.3 system using yum localinstall.

Testing the RPMs

To verify that everything worked as expected, I tested the RPMs using these steps:

  1. Using a clean CentOS 6.3 VM (built using the “Minimal Desktop” option), I used yum groupinstall to install the Virtualization, Virtualization Client, Virtualization Platform, and Virtualization Tools groups. This installed version 0.9.10 of libvirt.

  2. I then installed the updated version of libvirt using yum localinstall. I had to specify the dependencies manually on the command line; I anticipate that had I been using a real repository, this would not have been the case. The updated libvirt, sanlock, and libssh2 packages all installed correctly.

  3. I started the libvirtd service (it worked), and ran virsh --version. It returned version 1.0.1.

I imagine there might be more comprehensive/better ways of testing the RPMs that I built, but they seemed to work fine on my end. If anyone has any other suggestions for how we can double-check to ensure the packages are working correctly, feel free to speak up in the comments below. I also welcome any other corrections, suggestions, or questions in the comments. Courteous comments are always welcome.

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Technology Short Take #28

Thursday, January 10, 2013 in Macintosh, Microsoft, Networking, Security, Storage, Virtualization by slowe | 3 comments

Welcome to Technology Short Take #28, the first Technology Short Take for 2013. As always, I hope that you find something useful or informative here. Enjoy!

Networking

  • Ivan Pepelnjak recently wrote a piece titled “Edge and Core OpenFlow (and why MPLS is not NAT)”. It’s an informative piece—Ivan’s stuff is always informative—but what really drew my attention was his mention of a paper by Martin Casado, Teemu Koponen, and others that calls for a combination of MPLS and OpenFlow (and an evolution of OpenFlow into “edge” and “core” versions) to build next-generation networks. I’ve downloaded the paper and intend to review it in more detail. I’d love to hear from any networking experts who’ve read the paper—what are your thoughts?
  • Speaking of Ivan…it also appears that he’s quite pleased with Microsoft’s implementation of NVGRE in Hyper-V. Sounds like some of the other vendors need to get on the ball.
  • Here’s a nice explanation of CloudStack’s physical networking architecture.
  • The first fruits of Brad Hedlund’s decision to join VMware/Nicira have shown up in this joint article by Brad, Bruce Davie, and Martin Casado describing the role of network virutalization in the software-defined data center. (It doesn’t matter how many times I say or write “software-defined data center,” it still feels like a marketing term.) This post is fairly high-level and abstract; I’m looking forward to seeing more detailed and in-depth posts in the future.
  • Art Fewell speculates that the networking industry has “lost our way” and become a “big bag of protocols” in this article. I do agree with one of the final conclusions that Fewell makes in his article: that SDN (a poorly-defined and often over-used term) is the methodology of cloud computing applied to networking. Therefore, SDN is cloud networking. That, in my humble opinion, is a more holistic and useful way of looking at SDN.
  • It appears that the vCloud Connector posts (here and here) that (apparently) incorrectly identify VXLAN as a component/prerequisite of vCloud Connector have yet to be corrected. (Hat tip to Kenneth Hui at VCE.)

Servers/Hardware

Nothing this time around, but I’ll watch for content to include in future posts.

Security

  • Here’s a link to a brief (too brief, in my opinion, but perhaps I’m just being overly critical) post on KVM virtualization security, authored by Dell TechCenter. It provides some good information on securing the libvirt communication channel.

Cloud Computing/Cloud Management

  • Long-time VMware users probably remember Mike DiPetrillo, whose website has now, unfortunately, gone offline. I mention this because I’ve had this article on RabbitMQ AMQP with vCloud Director sitting in my list of “articles to write about” for a while, but some of the images were missing and I couldn’t find a link for the article. I finally found a link to a reprinted version of the article on DZone Enterprise Integration. Perhaps the article will be of some use to someone.
  • Sam Johnston talks about reliability in the cloud with a discussion on the merits of “reliable software” (software designed for failure) vs. “unreliable software” (more traditional software not designed for failure). It’s a good article, but I found the discussion between Sam and Massimo (of VMware) as equally useful.

Operating Systems/Applications

Storage

  • Want some good details on the space-efficient sparse disk format in vSphere 5.1? Andre Leibovici has you covered right here.
  • Read this article for good information from Andre on a potential timeout issue with recomposing desktops and using the View Storage Accelerator (aka context-based read cache, CRBC).
  • Apparently Cormac Hogan, aka @VMwareStorage on Twitter, hasn’t gotten the memo that “best practices” is now outlawed. He should have named this series on NFS with vSphere “NFS Recommended Practices”, but even misnamed as they are, the posts still have useful information. Check out part 1, part 2, and part 3.
  • If you’d like to get a feel for how VMware sees the future of flash storage in vSphere environments, read this.

Virtualization

  • This is a slightly older post, but informative and useful nevertheless. Cormac posted an article on VAAI offloads and KAVG latency when observed in esxtop. The summary of the article is that the commands esxtop is tracking are internal to the ESXi kernel only; therefore, abnormal KAVG values do not represent any sort of problem. (Note there’s also an associated VMware KB article.)
  • More good information from Cormac here on the use of the SunRPC.MaxConnPerIP advanced setting and its impact on NFS mounts and NFS connections.
  • Another slightly older article (from September 2012) is this one from Frank Denneman on how vSphere 5.1 handles parallel Storage vMotion operations.
  • A fellow IT pro contacted me on Twitter to see if I had any idea why some shares on his Windows Server VM weren’t working. As it turns out, the problem is related to hotplug functionality; the OS sees the second drive as “removable” due to hotplug functionality, and therefore shares don’t work. The problem is outlined in a bit more detail here.
  • William Lam outlines how to use new tagging functionality in esxcli in vSphere 5.1 for more comprehensive scripted configurations. The new tagging functionality—if I’m reading William’s write-up correctly—means that you can configure VMkernel interfaces for any of the supported traffic types via esxcli. Neat.
  • Chris Wahl has a nice write-up on the behavior of Network I/O Control with multi-NIC vMotion traffic. It was pointed out in the comments that the behavior Chris describes is documented, but the write-up is still handy, and an important factor to keep in mind in your designs.

I suppose I should end it here, before this “short take” turns into a “long take”! In any case, courteous comments are always welcome, so if you have additional information, clarifications, or corrections to share regarding any of the articles or links in this post, feel free to speak up below.

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Looking Back: 2012 Project Report Card

Monday, January 7, 2013 in General, Linux, Networking, Virtualization by slowe | 3 comments

About a year ago, I posted a look at my planned projects for 2012. Now, a year later, it’s time to review my progress (or lack thereof) and measure myself on how well I did (or didn’t) do on those projects.

First, let’s review the original project list:

  1. Learn to script in Perl.
  2. Learn to speak German.
  3. Become more familiar with Xen (and Open vSwitch and OpenStack).
  4. Pursue CCNP.

In my late June mid-year project update, I dropped the Perl scripting project simply because I had no practical applications driving the use of Perl. So, with that in mind, how did I do?

  1. Learn to speak German: Although I won’t say that I’ve actually learned to speak German, I have made some progress here. It’s not nearly the progress that I wanted to make, though—I wanted to be much farther along than I am. Grade: D

  2. Become more familiar with Xen, OVS, OpenStack: In retrospect, this project was overly broad, and therefore has mixed results. I ended up ditching Xen in favor of KVM, and made decent progress on that front. My work with Open vSwitch (OVS) was pretty good, probably the best out of the group. I still have quite a way to go with OpenStack, but I feel that time spent with KVM, OVS, and Libvirt helped build solid fundamentals for future progress. Grade: B

  3. Pursue CCNP: As I mentioned in the mid-year update, my goal was never to actually achieve CCNP this year, but simply to make progress. Regardless, my progress was abysmal. Grade: F

  4. Learn to work with Puppet: Not on my original project list, this is something that I nevertheless spent a fair amount of time pursuing. I’m not an expert (not anywhere close), but I feel like I did make reasonable progress. Grade: C

In summary: not very good!

So, what can I learn from these results?

  • First, the synergy of the projects really does make a difference. As readers noted in the comments on my original 2012 projects list, my choice of projects wasn’t synergistic, and this hampered efforts. Key takeaway: listen more closely to the advice of others!
  • Projects need to be more tightly defined. The “learn Xen, OVS, OpenStack” project was simply too broad, and encompassed too many different components. As a result, progress was mixed.
  • There are still some fundamental building blocks that I personally need to shore up. For example, my work with KVM, OVS, Libvirt, and Puppet exposed some gaps in my base Linux knowledge, and this is reflected in my progress.

In a (near-)future post, I’ll incorporate the progress on my 2012 projects and the key takeaways into my list of 2013 projects. Until then, I welcome any feedback or thoughts in the comments below.

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Examining Some Networking-Virtualization Chimeras

Tuesday, December 11, 2012 in Interoperability, Networking, Virtualization by slowe | 2 comments

I like to spend time examining the areas where different groups of technologies intersect. Personally, I find this activity fascinating, and perhaps that’s the reason that I find myself pursing knowledge and experience in virtualization, networking, storage, and other areas simultaneously—it’s an effort to spend more time “on the border” between various technologies.

One border, in particular, is very interesting to me: the border between virtualization and networking. Time spent thinking about the border between networking and virtualization is what has generated posts like this one, this one, or this one. Because I’m not a networking expert (yet), most of the stuff I generate is junk, but at least it keeps me entertained—and it occasionally prods the Really Smart Guys (RSGs) to post something far more intelligent than anything I can create.

Anyway, I’ve been thinking more about some of these networking-virtualization chimeras, and I thought it might be interesting to talk about them, if for no other reason than to encourage the RSGs to correct me and help everyone understand a little better.

<aside>A chimera, by the way, was a mythological fire-breathing creature that was part lion, part goat, and part serpent; more generically, the word refers to any sort of organism that has two groups of genetically distinct cells. In layman’s terms, it’s something that is a mix of two other things.</aside>

Here are some of the networking-virtualization chimeras I’ve concocted:

  • FabricPath/TRILL on the hypervisor: See this blog post for more details. It turns out, at least at first glance, that this particular combination doesn’t seem to buy us much. The push for large L2 domains that seemed to fuel FabricPath and TRILL now seems to be abating in favor of network overlays and L3 routing.

  • MPLS-in-IP on the hypervisor: I also wrote about this strange concoction here. At first, I thought I was being clever and sidestepping some issues by bringing MPLS support into the hypervisor, but in thinking more about this I realize I’m wrong. Sure, we could encapsulate VM-to-VM traffic into MPLS, then encapsulate MPLS in UDP, but how is that any better than just encapsulating VM-to-VM traffic in VXLAN? It isn’t. (Not to mention that Ivan Pepelnjak set the record straight.)

  • LISP on the hypervisor: I thought this was a really good idea; by enabling LISP on the hypervisor and essentially making the hypervisor an ITR/ETR (see here for more LISP info), inter-DC vMotion becomes a snap. Want to use a completely routed access layer? No problem. Of course, that assumes all your WAN and data center equipment are LISP-capable and enabled/configured for LISP. I’m not the only one who thought this idea was cool, either. I’m sure there are additional problems/considerations of which I’m not aware, though—networking gurus, want to chime in and educate me on what I’m missing?

  • OTV on the hypervisor: This one isn’t really very interesting, as it bears great similarity to VXLAN (both OTV and VXLAN, to my knowledge, use very similar frame formats and encapsulation schemes). Is there something else here I’m missing?

  • VXLAN on physical switches: This one is interesting, even necessary according to some experts. Enabling VXLAN VTEP (VXLAN Tunnel End Point) termination on physical switches might also address some of the odd traffic patterns that would result from the use of VXLAN (see here for a simple example). Arista Networks demonstrated this functionality at VMworld 2012 in San Francisco, so this particular networking-virtualization mashup is probably closer to reality than any of the others.

  • OpenFlow on the hypervisor: Open vSwitch (OVS) already supports OpenFlow, so you might say that this mashup already exists. It’s not unreasonable to think Nicira might port OVS to VMware vSphere, which would bring an OpenFlow-compatible virtual switch to a much larger installed base. The missing piece is, of course, an OpenFlow controller. While an interesting mental exercise, I’m keenly interested to know what sort of real-world problems this might help solve, and would love to hear from any OpenFlow experts out there what they think.

  • Virtualizing physical switches: No, I’m not talking about running switch software on the hypervisor (think Nexus 1000V). Instead, I’m thinking more along the lines of FlowVisor, which in effect virtualizes a switch’s control plane so that multiple “slices” of a switch can be independently controlled by an external OpenFlow controller. If you’re familiar with NetApp, think of their “vfiler” construct, or think of the Virtual Device Contexts (VDCs) in a Nexus 7000. However, I’m thinking of something more device-independent than Nexus 7000 VDCs. As more and more switches move to x86 hardware, this seems like it might be something that could really take off. Multi-tenancy support (each “virtual switch instance” being independently managed), traffic isolation, QoS, VLAN isolation…lots of possibilities exist here.

Are there any other groupings that are worth exploring or discussing? Any other “you got your virtualization peanut butter in my networking chocolate” combinations that might help address some of the issues in data centers today? Feel free to speak up in the comments below. Courteous comments are invited and encouraged.

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Technology Short Take #27

Thursday, December 6, 2012 in Linux, Networking, Security, Virtualization by slowe | 1 comment

Welcome to Technology Short Take #27! This is my usual collection of links, thoughts, rants, and ideas about data center-related technologies. Here’s hoping you find something useful!

Networking

  • If you’re interested in learning more about OpenFlow and software-defined networking but need to do this on a shoestring budget in your home lab, a number of guides have been written to help out. I haven’t personally used any of these guides yet, but I’m working my way in that direction. (I needed to fill in some other knowledge gaps first.) First up is Brent Salisbury’s how to build an SDN lab without needing OpenFlow hardware. Brent is creating some fantastic content that I’ve found extremely useful. His earlier post on getting started with OpenFlow and Open vSwitch tutorial lab is also quite good. Another good resource is Dan Hersey’s guide to building an SDN-based private cloud in an hour. I encourage you to have a look at these posts if you’re at all interested in any of these technologies.
  • Bruce Davie and Martin Casado (with Nicira, now part of VMware) have written a post comparing the VXLAN and STT tunneling protocols. Not unsurprisingly, one of the key advantages of STT that’s highlighted is its improved performance due to TSO support in NIC hardware. VXLAN, on the other hand, is seeing broader adoption across multiple vendors. There’s no mention of NVGRE (or just plain GRE).
  • Related to the bare metal provisioning work (see below under “Servers/Hardware”), Mirantis also detailed some bare-metal networking stuff they’ve done for OpenStack in relation to the use of bare metal nodes.

Servers/Hardware

  • Mirantis published an article discussing a framework they built for bare-metal provisioning with OpenStack that allows OpenStack to place workloads onto bare-metal nodes instead of onto a hypervisor. It’s interesting work, but unfortunately it looks like this work won’t be returned to the community (it was developed for one or more of their clients). There are also a few follow-up posts, such as this one on placement control and multi-tenancy isolation and this one on preparing images for bare metal nodes. Also see the “Networking” section above for a related post on the networking aspects involved.

Security

I don’t have anything for this area this time around, but I’ll stay alert for articles to add next time. Feel free to share something in the comments!

Cloud Computing/Cloud Management

  • I might have mentioned this before, but Ken Pepple’s OpenStack Folsom architecture post is just awesome. It’s well worth reading and reviewing in depth.
  • This OpenStack-on-Debian HOWTO is a bit older (and probably out of date), but it does give a decent overview of the components that are involved and—via the configuration—how they relate to each other. While the details for installing a current version of OpenStack are likely to be different now, you might still find this conceptually helpful.
  • These articles are a bit long in the tooth, but CSS Corp has a useful series of articles on bundling various Linux distributions for use with OpenStack: bundling CentOS, bundling CentOS with VNC, bundling Debian, and bundling OpenSUSE. It would be interesting to me to see how much of this, if any, could be automated with something like Puppet. If any enterprise Puppet experts want to give it a go, I’d be happy to publish a guest blog post for you with full details on how it’s done.
  • Much like there are some great “how to’s” on how to run an SDN lab (see the Networking section earlier), there are also some great write-ups on doing the same for OpenStack. For example, Cody Bunch published this article on running OpenStack Private Cloud on ESXi, and Brent Salisbury (there he is again!) posted an older guide to OpenStack Essex on Ubuntu on VirtualBox as well as a newer guide to OpenStack DevStack on Fusion.

Operating Systems/Applications

Storage

  • I don’t fully understand all the details involved, but this post on changes in block protocol scalability in Xen outlines what sounds like good progress in improving efficiency.
  • This article is a bit older, published at the start of October, but it talks about an interesting project (product?) by Qlogic called “Mt. Rainier.” (Stu Miniman of Wikibon has more information here as well.) Apparently, “Mt. Rainier” will allow customers to combine PCIe-based SSD storage inside servers into a “virtual SAN” (now there’s an original and not over-used term). The really interesting aspect, in my opinion, is the use of “Mt. Rainier” to create shared caches across servers. Is this the beginning of the data center fractal edge?

Virtualization

  • Big news in the QEMU world: In the QEMU 1.3 release, the QEMU-KVM and QEMU projects have been merged. Why is this important? It’s first necessary to understand the relationship between QEMU and KVM. KVM is the set of kernel modules that leverage hardware virtualization functionality inside Intel and AMD CPUs, and it makes possible the virtualization of closed-source operating systems like Windows. QEMU, on the other hand, is needed to emulate everything else that a VM needs: networking, storage, USB, keyboard, mouse, etc. Both KVM and QEMU are needed for a full virtualization solution. Until the 1.3 release, QEMU (without hardware acceleration via KVM) was one branch, and QEMU-KVM (with KVM hardware acceleration) was a separate branch. The QEMU 1.3 release completes an effort to merge both efforts into a single development tree.
  • The merge of QEMU and QEMU-KVM isn’t the only cool thing happening with QEMU; also included in the 1.3 release is GlusterFS integration. This integration dramatically improves GlusterFS performance by allowing QEMU’s block layer to communicate directly with the Gluster backend without going through the userspace FUSE components.
  • Erik Scholten of VMGuru.nl has posted a good hypervisor feature comparison document. It includes RHEV 3.1 in the comparison, even though RHEV 3.1 wasn’t released (was still in beta) at the time the comparison was written.
  • Speaking of RHEV: apparently RHEV 3.1 was released yesterday (Wednesday, December 4, 2012), although I haven’t been able to find any sort of official press release or announcement.
  • Debunking an argument I’ve heard quite a bit is this article by Frank Denneman on using SIOC with multiple datastores backed by a single pool of disks.
  • Need to compact a virtual hard disk in Windows 8/Windows Server 2012? Ben Armstrong shows how here.
  • I enjoyed this article by Josh Townsend on using SUSE Studio and HAProxy to create a (free) open source load balancing solution for VMware View.

That’s it for this time around; no need to overwhelm you with too much information! Besides, I have to keep a few items around for Technology Short Take #28…

As always, comments, thoughts, rants, or corrections are welcome below.

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