December 2009

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So Long Status Quo

Monday, December 28, 2009 in General, Personal by slowe | 53 comments

Fans of Christian artist Nichole Nordeman will recognize the title of this post as a line coming from the chorus of her hit song “Brave” (from the album of the same name). The words go something like this:

So long status quo,
I think I just let go…

I think that these words are particularly applicable given the decision that I’ve just made. Talk about letting go of the status quo! You see, for the largest part of my professional career I’ve worked in the partner/reseller community. Working in the partner/reseller community has been great; you get to meet lots of different people, work in a variety of environments, and constantly chase the latest technologies. Still, the demands of the partner/reseller community almost force you, as a technical person, to be “a mile wide but only an inch deep,” meaning you know only a little bit about a lot of things. That can be difficult for some people, like me, who like to really know products. A lot of times, you just don’t get the time to do that. In a couple of weeks, though, all that changes.

In a couple of weeks, I’ll be joining EMC Corporation as a VMware-Cisco Solutions Principal. Yes, that’s right—I’m joining Chad’s team (sometimes referred to as “Chad’s Army”). I can’t tell you yet if I’m a warrior, a monk, a warrior-monk, or something else entirely; I imagine that will be just one of many things that I will discover in the coming months and years.

I can tell you that I’m very excited. As indicated by my job title, I’ll be focusing on VMware-Cisco-EMC and where these three companies converge. That means lots of exposure to Vblocks and other cool technologies that smart people in Hopkinton, San Jose, and Palo Alto are building right now as I write. Of course, I’ll be working directly with the VMware specialists on Chad’s team. If you’ve met some of these guys, you’ll know what a treat that is—there is some great talent on this team.

You might be wondering how this will affect my blogging. That was a concern that I shared while discussing this opportunity. The bottom line is that it won’t. I won’t let it. Sure, you’ll see a new disclaimer appear in the sidebar and on the About page that indicates this is a personal blog and not an EMC blog, etc., but otherwise my goal is to continue to share solid, helpful technical content with my readers. I intend to continue to provide viewpoints that are as impartial as possible, and to live up to Steve Chamber’s comments about being an anti-protocol passionista. I’m sure that I will be accused of being an EMC fanboy (that started months ago!) or a VMware fanboy, but I do aim to be as impartial and even-balanced as I possibly can be. Of course, I am human and prone to error from time to time, so don’t be too harsh on me.

To all my friends and colleagues at ePlus, it has been a tremendous pleasure working with you. Many of you I have known personally and worked with for more than ten years. It’s like we are family! I will sincerely miss your friendship and your support. ePlus is a great company with some fantastic talent, and I wish ePlus and all of you nothing but the best!

So long, status quo…

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A Bit Harsh, Don’t You Think?

Wednesday, December 23, 2009 in Virtualization by slowe | 11 comments

Yesterday, Alex Barrett of TechTarget posted a tweet about her predictions for 2010:

No wishy washy 2010 predictions from me: VMware will cut prices, and Citrix will give up on XenServer: http://bit.ly/75vDxc

The link in the tweet corresponds to this TechTarget article in which Alex predicts that VMware will cut prices and Citrix will dump XenServer and focus instead on its management products like Citrix Essentials. Citrix Essentials, as you probably know, already supports Microsoft Hyper-V. Alex’s prediction is not an unusual one; others have made this prediction before. Quite honestly, based on the progress we are seeing on XenServer’s development, I can see the logic behind Alex’s prediction.

Then along comes Simon Crosby and posts a rebuttal to Alex’s prediction, citing XenServer’s growth, industry partnerships, and projected development goals. OK, that’s fine and all; I would certainly expect Simon to be an ardent supporter of Xen and XenServer. I don’t take issue with his rebuttal; what I take issue with is this statement:

I think I’ve concluded that there are a few people whose predictions about the future I will never believe. They are precisely those who are compensated based on clicks and not insight, and who seldom take the time to check for data or accuracy.

To prevent any question of the individual about whom he was speaking, Simon added a hyperlink (recreated in the quote above) to point to Alex Barrett’s author page at TechTarget.

Ouch—that’s a bit harsh, don’t you think? It’s just bad form to say something like that about someone. First of all, a prediction isn’t exactly something you can “check for data or accuracy”; it’s a prediction. No one, including me, begrudges any vendor from defending itself. But there are ways of defending yourself without personally attacking others. There are ways to disagree respectfully and courteously. There are those out there that might want to try this approach.

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Virtualization Short Take #32

Tuesday, December 22, 2009 in Networking, Storage, Virtualization by slowe | No comments

Here it is—the last Virtualization Short Take of 2009! This is just a small collection of various virtualization-related links and articles that I’ve gathered over the last few weeks (OK, maybe more than a few weeks).

  • Scott Drummonds posted a good article with a performance comparison of thick provisioned disks vs. thin provisioned disks. This is good information and helps to clear up a lot of misinformation about the behavior of thin provisioned disks.
  • Interested in using the software iSCSI initiator with a dvSwitch and multiple paths? This article can give you the information you need to get started.
  • Frank Denneman has a great article providing some details on memory reservations and memory usage. It’s definitely worth a read, as is this post on the impact of guest OS type mismatch. See, there is a reason why it’s important to make sure you select the correct guest OS type when creating VMs.
  • I’ve written about the paravirtualized SCSI (PVSCSI) driver before, but Scott Sauer over at Virtual Insanity has a great two-part series on PVSCSI that is definitely worth a read (part 1 and part 2).
  • Although a bit dated now, Dave Lawrence has a great review of some of November’s technical white papers. He references the thin provisioning performance paper that’s also referenced in Scott Drummond’s post above, as well as a white paper on optimizing SRM performance. Thanks for bringing our attention to these documents, Dave!
  • The release of VMware View 4 brings with it PCoIP, which is supposed to bring enhanced performance over older display protocols. Unfortunately, everything I was hearing was that PCoIP was incompatible with many WAN acceleration solutions. So I was quite puzzled at this press release. Reading the press release a bit more closely, though, it would seem that Expand’s solution doesn’t actually optimize or accelerate PCoIP; rather, it enables it to be tunneled and applies Quality of Service (QoS). Something is better than nothing, I guess.
  • Rick Scherer describes a strange issue with vCenter Server 4.0 Update 1 and VMware ESXi 4.0 Update 1. Rick was seeing a number of strange symptoms, including ESXi hosts suddenly disconnecting from vCenter Server. Last time I checked Rick still hadn’t identified the root cause, although the symptoms he was seeing have since disappeared.
  • Stu provides a thorough explanation of why VMware is recommending not to install vCenter Server 4.0 Update 1 when managing VMware ESXi 4.0 hosts.
  • Need to install the HP Management Agents on VMware ESX 4.0? Here are some helpful instructions.
  • Nigel Poulton has started a great series on rack area networks (RANs), of which a key component is I/O virtualization. So far, Nigel has published part 1 (introducing the concept of a RAN), part 2 (IOV’s role in a RAN), and part 3 (IOV and hairpin turns). Part 2, in particular, has a good discussion of SR-IOV and MR-IOV. Nigel’s discussion of SR-IOV is a good complement to my own.
  • Greg Schulz also has a lengthy article on I/O virtualization.
  • Curious to know why NUMA is important with vSphere? Network Computing blogger Jake McTigue (with whom I had the honor of participating on a recent virtual networking webcast) has a good overview of NUMA and what it means for virtualized environments. It’s worth a read if you’re not already familiar with NUMA.
  • Need more information on storage alignment and VMFS block sizes? Check out this VIOPS document.

I also have a whole list of other links that I haven’t had the chance to read yet but that look like they might be interesting or useful:

A handy new addition to the Command Line Tool for View 4
Whats what in VMware View and VDI Land
How to get PCoIP with View 4 to work every time!
Revisiting the Components of the Cisco Nexus 1000v
File Virtualization… The short primer
Is Your Blade Ready for Virtualization? A Math Lesson
RSA SecureBook for VMware View hardening now publicly available!

I guess that’s enough for now. If you have any other useful, unique, or interesting virtualization-related links, feel free to share them in the comments. Thanks for reading!

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Growl Notifications with Snow Leopard Mail and Exchange

Thursday, December 10, 2009 in Macintosh, Messaging by slowe | 2 comments

Like many Mac users, I use Growl to provide customizable, centralized notifications for events occurring on my system. Rather than use the Growl team’s GrowlMail plug-in, I use a custom AppleScript that I wrote that provide new message notifications via Growl. It’s not a terribly advanced script; it just provides per-message notifications for each message received, unless I receive more than 5 messages at a time in which case the script just provides a summary notification. It’s worked very well for me for quite some time.

Now, following my upgrade to a new MacBook Pro running Snow Leopard, I’m finding that the script has an interesting flaw: when new messages are received via my Exchange account at work, the script notifies me using information from the previous message received on that account rather than the information from the newly-received message. I know that it’s not the script because notifications for all other accounts work just fine. Only the Exchange account—which uses Snow Leopard’s new Exchange support for connectivity—is affected.

Has anyone else seen this? If so, does anyone have a fix?

UPDATE: I wasn’t able to make Growl notifications invoked from an AppleScript work properly with my Exchange account, so I tried switching to GrowlMail. Unfortunately, GrowlMail has problems with Snow Leopard 10.6.2 that can only be fixed using the Terminal commands in this article. After getting GrowlMail recognized by Mail.app, notifications started appearing correctly for all accounts including my Exchange account.

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Snow Leopard, Time Machine, and Iomega ix4-200d

Wednesday, December 9, 2009 in Macintosh, Storage by slowe | 8 comments

Chad Sakac of EMC (visit his weblog here) recently sent me an Iomega ix4-200d storage unit. Considering that I didn’t need it for my VMware lab—which runs both EMC and NetApp storage arrays—I pressed it into service at home. I can’t tell you how useful it’s been, especially the built-in Time Machine support. Making my three-year-old MacBook Pro running Leopard (Mac OS X 10.5) work with the Iomega’s Time Machine implementation was a piece of cake: point it at the ix4-200d and you’re all set. It’s been great.

Recently, though, I picked up a new MacBook Pro running Snow Leopard. Unfortunately, due to some “under the covers” changes from Leopard to Snow Leopard, making your Snow Leopard-based Mac use the ix4-200d for Time Machine backups isn’t quite so straightforward. Thankfully, due to these instructions, I was able to make it work without too much effort. Here’s how.

First, you’ll need to create a sparse disk image using the following command from Terminal.app:

hdiutil create -size 500G -fs HFS+J -volname 'Time Machine' -type SPARSEBUNDLE <filename>.sparsebundle

Leopard required that the name of the sparse disk image be a concatenation of the computer’s name and the MAC address of the Ethernet interface (en0) on the system. (By the way, you have to use the MAC address of en0 even if you are performing wireless backups over en1.) It appears that Snow Leopard does not have this restriction. I followed it anyway, just in case. hdiutil will create it in whatever directory you are in when you run the command. If you aren’t in the TimeMachine directory on your ix4-200d (which would have a path of /Volumes/TimeMachine on your local Mac), then you’ll need to copy the sparse disk image later. That’s OK.

Second, you’ll need to create a file named com.apple.TimeMachine.MachineID.plist and copy that into the sparse disk image. The contents of this file should look like this:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>com.apple.backupd.HostUUID</key>
<string>System UUID Here</string>
</dict>
</plist>

You’ll need to put your system’s UUID here; you can get this value from System Profiler. Once you’ve created this file with the appropriate values, copy it into the sparse disk image you created. I did this with the Finder and it works fine, but if you want to use Terminal.app you can use this command:

cp com.apple.TimeMachine.MachineID.plist <filename>.sparsebundle

Finally, copy—if necessary—the sparse disk image from wherever you created it to the TimeMachine share on the Iomega ix4-200d. Make sure you’ve mounted the TimeMachine share via AFP and then copy the sparsebundle over using this command:

cp -pfr <filename>.sparsebundle /Volumes/TimeMachine/<filename>.sparsebundle

After you’ve completed all these steps, you can go into the Time Machine preferences and activate Time Machine against the ix4-200d. It worked seamlessly for me on Mac OS X 10.6.2, but your mileage may vary.

I also found this site and this site helpful in confirming the necessary contents of the com.apple.TimeMachine.MachineID.plist file, which is really the key to making it work in Snow Leopard.

I hope someone finds this useful!

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VMware vSphere 4 Administration Instant Reference Now Available

Wednesday, December 9, 2009 in Collaboration, Virtualization by slowe | 6 comments

This afternoon UPS delivered to my door a box full of copies of my latest book, written in partnership with Jase McCarty and Matthew Johnson. VMware vSphere 4 Administration Instant Reference is a hands-on how-to guide for vSphere administrators. The book will be especially helpful for newer administrators who are still learning their way around VMware vSphere and the vSphere Client, but I think even experienced administrators will still find some useful information tucked away here and there. Jase, Matthew, and I worked very hard on this book, and we hope that you find it useful.

Generally, the fact that I received my copies means that the book is in the warehouse and will start shipping very soon. You can pre-order the book right now on Amazon.com and it should start shipping very soon. Amazon hasn’t yet updated the site to show an anticipated shipping date, but I would strongly imagine it will start shipping very soon. Go order a copy now for the VMware geek in your life and give it as a Christmas gift!

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Multiport Uplink Driver

Friday, December 4, 2009 in Networking, Virtualization by slowe | 2 comments

Virtual I/O is getting more attention. This press release from Chelsio crossed my desk this morning:

Virtual Multi-port Software allows for consolidation of switch ports and cabling by using 10Gb infrastructure while maintaining the existing Gigabit-based ESX setup. The software enables the consolidation by keeping the infrastructure update completely transparent to the ESX hypervisor, enabling a 10Gb adapter to appear to the hypervisor as eight virtual Gigabit adapters. By offloading the tasks performed by the hypervisor, the Chelsio adapters can deliver the best I/O performance for virtualized applications.

There’s no mention of SR-IOV (more information on SR-IOV is available in this post), so I’m guessing that this is a proprietary technology similar to what HP is using in Virtual Connect Flex-10. The key difference with HP Virtual Connect Flex-10 and the Chelsio solution is that Flex-10 doesn’t require any software support in the OS or hypervisor, whereas Chelsio’s solution does require software support (as does SR-IOV). Nevertheless, it’s clear that I/O virtualization—even relatively simple forms of I/O virtualization such as this—is gaining more and more attention.

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What is SR-IOV?

Wednesday, December 2, 2009 in Virtualization by slowe | 15 comments

I/O virtualization is a topic that has received a fair amount of attention recently, due in no small part to the attention given to Xsigo Systems after their participation in the Gestalt IT Tech Field Day. While Xsigo uses InfiniBand as their I/O virtualization mechanism, there are other I/O virtualization technologies out there as well. One of these technologies is Single Root I/O Virtualization (SR-IOV).

So what is SR-IOV? The short answer is that SR-IOV is a specification that allows a PCIe device to appear to be multiple separate physical PCIe devices. The SR-IOV specification was created and is maintained by the PCI SIG, with the idea that a standard specification will help promote interoperability.

SR-IOV works by introducing the idea of physical functions (PFs) and virtual functions (VFs). Physical functions (PFs) are full-featured PCIe functions; virtual functions (VFs) are “lightweight” functions that lack configuration resources. (I’ll explain why VFs lack these configuration resources shortly.)

SR-IOV requires support in the BIOS as well as in the operating system instance or hypervisor that is running on the hardware. Until very recently, I had been under the impression that SR-IOV was handled solely in hardware and did not require any software support; unfortunately, I was mistaken. Software support in the operating system instance or hypervisor is definitely required. To understand why, I must talk a bit more about PFs and VFs.

I mentioned earlier that PFs are full-featured PCIe functions; they are discovered, managed, and manipulated like any other PCIe device. PFs have full configuration resources, meaning that it’s possible to configure or control the PCIe device via the PF, and (of course) the PF has full ability to move data in and out of the device. VFs are similar to PFs but lack configuration resources; basically, they only have the ability to move data in and out. VFs can’t be configured, because that would change the underlying PF and thus all other VFs; configuration can only be done against the PF. Because VFs can’t be treated like a full PCIe device, then the OS or hypervisor instance must be aware that they are not full PCIe devices. Hence, OS or hypervisor support is required for SR-IOV so that the OS instance or hypervisor can properly detect and initialize PFs and VFs correctly and appropriately. At this time, SR-IOV support is only found in some of the open source Linux kernels; this means it will find its way into KVM and Xen first. I do not have a timeframe for SR-IOV support in VMware vSphere or Microsoft Hyper-V.

So, putting this all together: what do you get when you have an SR-IOV-enabled PCIe device in a system with the appropriate BIOS and hardware support and you’re running an OS instance or hypervisor with SR-IOV support? Basically, you get the ability for that PCIe device to present multiple instances of itself up to the OS instance or hypervisor. The number of virtual instances that can be presented depends upon the device.

The PCI SIG SR-IOV specification indicates that each device can have up to 256 VFs. Depending on the SR-IOV device in question and how it is made, it might present itself in a variety of ways. Consider these exampes:

  • A quad-port SR-IOV network interface card (NIC) presents itself as four devices, each with a single port. Each of these devices could have up to 256 VFs (single port NICs) for a theoretical total of 1,024 VFs. In this case, each VF would essentially represent a single NIC port.
  • A dual-port SR-IOV host bus adapter (HBA) presents itself as one device with two ports. With 256 VFs, this would result in 512 HBA ports spread across 256 dual-port virtual HBAs.

These are, of course, theoretical maximums. Because each VF requires actual hardware resources, practical limits are much lower. Currently, 64 VFs seems to be the upper limit for most devices.

In situations where VFs represent additional NIC ports or HBA ports, other technologies must also come into play. For example, suppose that you had an SR-IOV-enabled Fibre Channel HBA in a system; that HBA could present itself as multiple, separate HBAs. Of course, because these logical HBAs would still share a single physical HBA port, you’d need NPIV (more information here) to support running multiple WWNs and N_Port_IDs on a single physical HBA port.

Similarly, you might have a Gigabit Ethernet NIC with SR-IOV support. That NIC could theoretically (according to the PCI SIG SR-IOV specification) present itself as up to 256 virtual NICs. Each of these NICs would be discrete and separate to the OS instance or hypervisor, but the physical Ethernet switch wouldn’t be aware of the VFs. Switches wouldn’t, by default, reflect some types of traffic arriving inbound on a port (from one VF) back out on the same port (to another VF). This could create some unexpected results.

SR-IOV does have its limitations. The VFs have to be the same type of device as the PF; you couldn’t, for example, have VFs that presented themselves as one type of device when the PF presented itself as a different type of device. Also, recall from earlier that VFs generally can’t be used to configure the actual physical device, although the extent to which this is true depends upon the implementation. The SR-IOV specification allows some leeway in the actual implementation; this leeway means that some SR-IOV-enabled NICs may also have VF switching functionality present (where the NIC could switch traffic between VFs without the assistance of a physical switch) while other NICs may not have VF switching functionality present (in which case VFs would not be able to communicate with each other without the presence of a physical switch).

I do want to point out that SR-IOV is related to, but not the same as, hypervisor bypass (think VMDirectPath in VMware vSphere). SR-IOV enables hypervisor bypass by providing the ability for VMs to attach to a VF and share a single physical NIC. However, the use of SR-IOV does not automatically indicate the hypervisor bypass will also be involved. Hypervisor bypass is a topic that I’m sure I will discuss in more detail in the near future.

Finally, it’s worth noting that the PCI SIG is also working on a separate IOV specification that allows multiple systems to share PCIe devices. This specification, known as Multi-Root IOV (MR-IOV), would enable multiple systems to share PCIe VFs. I hope to have more information on MR-IOV in the near future as well.

You now should have a basic understanding of SR-IOV, what it does, what is necessary to support it, and some of the benefits and drawbacks that SR-IOV creates. Feel free to post any questions you have about SR-IOV in the comments and I’ll do my best to get answers for you.

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My Number One Yojimbo Complaint

Wednesday, December 2, 2009 in Macintosh by slowe | 1 comment

After a couple of weeks using Yojimbo from Bare Bones Software, I’m really liking the application. I’m finding it useful and helpful to have an “anything bucket” into which I can toss bits and tidbits of information on an as-needed basis. It’s become incredibly useful for quickly throwing in a URL from Camino or NetNewsWire that I can come back and review later.

However, I do have one major complaint with Yojimbo: it doesn’t honor default applications. I don’t use Preview for PDF files; I use Skim. I don’t use TextEdit for text files; I use TextMate. When I double-click a PDF file in the Finder, Skim opens. When I double-click a text file in the Finder, TextMate opens. Yet, I can’t open PDFs or text notes in Yojimbo in those applications. Instead, Yojimbo forces me to use Preview and TextEdit. C’mon, Bare Bones! Can’t you just add a feature that tells Yojimbo to honor the default apps?

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vSphere 4.0 Quick Start Guide

Wednesday, December 2, 2009 in Virtualization by slowe | 6 comments

It’s funny how ideas evolve. Months ago, the idea of a “super blog” came up in a series of Twitter conversations. Stephen Foskett (@sfoskett on Twitter) ran with that idea to create Gestalt IT; Duncan Epping (@DuncanYB on Twitter) ran with that idea to create vSphere 4.0 Quick Start Guide: Shortcuts down the path of Virtualization.

I didn’t, unfortunately, get a chance to actually have a look at the QSG (easier to type than “Quick Start Guide”) until this past week. Some preview copies were given away at VMworld 2009 in San Francisco, but I didn’t manage to get a copy. After having some time to review it briefly this past week—I still haven’t read the entire book cover-to-cover—I must say that I am impressed.

What I’ve seen of the book is thorough, detailed, and takes a “common sense” approach to providing how-to information on VMware vSphere. In this respect, it’s a lot like my second book, VMware vSphere 4 Administration Instant Reference, which I co-wrote with Jase McCarty and Matthew Johnson and which will be officially released later this month (pre-orders available on Amazon right now). One thing that I do like about the QSG is the integration of PowerCLI at every stage. This makes it super-easy for aspiring PowerCLI gurus to learn their way around the cmdlets and how to put them together. It’s an idea I wish I’d thought of doing! Overall, given the breadth of coverage and the detail provided, the QSG does a great job.

If you’re looking for a how-to guide on VMware vSphere, buy both my book and the QSG for the most extensive coverage. Both books—mine or the QSG—provide excellent coverage on their own; the QSG certainly excels in the practical application of PowerCLI to the administration tasks. Either would be a great choice. To Duncan, Thomas, Dave, Stuart, Alan, and Bernie: great work, guys!

Here are links to both books on Amazon.com:

vSphere 4.0 Quick Start Guide: Shortcuts down the path of Virtualization

VMware vSphere 4 Administration Instant Reference

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