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VMware vSphere Generates Insane Amounts of I/O

Monday, May 18, 2009 in Storage, Virtualization by slowe | 8 comments

The news has hit the Internet in various places, but I wanted to point it out here because it does help to debunk the myth that virtualization can’t handle all workload. What’s the news? EMC and VMware have jointly demonstrated that a single VMware vSphere host running just three virtual machines can drive just above 350,000 I/O operations per second (IOPS).

I’ll let that sink in for just a moment. In case you don’t understand just how significant that number is, consider that a typical Fibre Channel drive can sustain somewhere just below 200 IOPS (and that’s being a bit generous). At 200 IOPS per drive, driving 350,000 IOPS would require 1,750 drives. (Fortunately, EMC used Enterprise Flash Drives (EFDs), so far fewer drives were required.) I would wonder how many of us have actually seen a storage array with that many drives.

Chad Sakac of EMC covered the tests on his blog here; the VMware Performance blog also discussed the results in detail as well.

So, next time you are thinking that VMware vSphere can’t handle your database workloads, keep these figures in mind. Or, if you’re a consultant like me, use these figures next time your customer says that virtualization can’t handle I/O-intensive workloads. This looks like pretty definitive results to me.

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Sanbolic Brings Snapshots to Melio FS

Tuesday, May 5, 2009 in Microsoft, Storage by slowe | 9 comments

Sanbolic is continuing to differentiate its clustered file system, Melio FS, in advance of the rudimentary clustered file system Microsoft plans on introducing in Windows Server 2008 R2. In an announcement last week, Sanbolic announced support for fully journaled snapshots. This functionality allows any server accessing the clustered file system to invoke a snapshot. The new snapshot functionality provides support for VSS and “full industry standard APIs,” although I’m not really sure what those “full industry standard APIs” are exactly.

You can download the full press release describing the new functionality here.

Separately, Sanbolic also announced that Melio FS fully supports Microsoft System Center Virtual Machine Manager 2008; more information on that is also available.

Now, if only Sanbolic would port Melio FS to VMware ESX/ESXi, then we could have some really interesting discussions. Snapshot functionality built into the shared file system, anyone?

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3010: A MultiStore Primer

Wednesday, April 8, 2009 in Storage, Virtualization by slowe | 16 comments

This session describes NetApp’s MultiStore functionality. MultiStore is the name given to NetApp’s functionality for secure logical partitioning of network and storage resources. The presenters for the session are Roger Weeks, TME with NetApp, and Scott Gelb with Insight Investments.

When using MultiStore, the basic building block is the vFiler. A vFiler is a logical construct within Data ONTAP that contains a lightweight instance of the Data ONTAP multi-protocol server. vFilers provide the ability to securely partition both storage resources and network resources. Storage resources are partitioned at either the FlexVol or Qtree level; it’s recommended to use FlexVols instead of Qtrees. (The presenters did not provide any further information beyond that recommendation. Do any readers have more information?) On the network side, the resources that can be logically partitioned are IP addresses, VLANs, VIFs, and IPspaces (logical routing tables).

Some reasons to use vFilers would include storage consolidation, seamless data migration, simple disaster recovery, or better workload management. MultiStore integrates with SnapMirror to provide some of the functionality needed for some of these use cases.

MultiStore uses vFiler0 to denote the physical hardware, and vFiler0 “owns” all the physical storage resources. You can create up to 64 vFiler instances, and active/active clustered configurations can support up to 130 vFiler instances (128 vFilers plus 2 vFiler0 instances) during a takeover scenario.

Each vFiler stores its configuration in a separate FlexVol (it’s own root vol, if you will). All the major protocols are supported within a vFiler context: NFS, CIFS, iSCSI, HTTP, and NDMP. Fibre Channel is not supported; you can only use Fibre Channel with vFiler0. This is due to the lack of NPIV support within Data ONTAP 7. (It’s theoretically possible, then, that if/when NetApp adds NPIV support to Data ONTAP that Fibre Channel would be supported within vFiler instances.)

Although it is possible to move resources between vFiler0 and a separate vFiler instance, doing so may impact client connections.

Managing vFilers appears to be the current weak spot; you can manage vFiler instances using the Data ONTAP CLI, but vFiler instances don’t have an interactive shell. Therefore, you have to direct commands to vFiler instances via SSH or RSH or using the vFiler context in vFiler0. You access the vFiler context by prepending the “vfiler” keyword to the commands at the CLI in vFiler0. Operations Manager 3.7 and Provisioning Manager can manage vFiler instances; FilerView can start, stop, or delete individual vFiler instances but cannot direct commands to an individual vFiler. If you need to manage CIFS on a vFiler instance, you can use the Computer Management MMC console to connect remotely to that vFiler instance to manage shares and share permissions, just as you can with vFiler0 (assuming CIFS is running within the vFiler, of course).

IPspaces are a logical routing construct that allow each vFiler to have its own routing table. For example, you may have a DMZ vFiler and an internal vFiler, each with their own, separate routing table. Up to 101 IPspaces are supported per controller. You can’t delete the default IPspace, as it’s the routing table for vFiler0. It is recommended to use VLANs and/or VIFs with IPspaces as a best practice.

One of the real advantages of using MultiStore and vFilers is the data migration and disaster recovery functionality that it enables when used in conjunction with SnapMirror. There are two sides to this:

  • “vfiler migrate” allows you to move an entire vFiler instance, including all data and configuration, from one physical storage system to another physical storage system. You can keep the same IP address or change the IP address. All other network identification remains the same: NetBIOS name, host name, etc., so the vFiler should look exactly the same across the network after the migration as it did before the migration.
  • “vfiler dr” is similar to “vfiler migrate” but uses SnapMirror to keep the source and target vFiler instances in sync with each other.

It makes sense, but you can’t use “vfiler dr” or “vfiler migrate” on vFiler0 (the physical storage system). My own personal thought regarding “vfiler dr”: what would this look like in a VMware environment using NFS? There could be some interesting possibilities there.

With regard to security, a Matasano security audit was performed and the results showed that there were no vulnerabilities that would allow “data leakage” between vFiler instances. This means that it’s OK to run a DMZ vFiler and an internal vFiler on the same physical system; the separation is strong enough.

Other points of interest:

  • Each vFiler adds about 400K of system memory, so keep that in mind when creating additional vFiler instances.
  • You can’t put more load on a MultiStore-enabled system than a non-MultiStore-enabled system. The ability to create logical vFilers doesn’t mean the physical storage system can suddenly handle more IOPS or more capacity.
  • You can use FlexShare on a MultiStore-enabled system to adjust priorities for the FlexVols assigned to various vFiler instances.
  • As of Data ONTAP 7.2, SnapMirror relationships created in a vFiler context are preserved during a “vfiler migrate” or “vfiler dr” operation.
  • More enhancements are planned for Data ONTAP 7.3, including deduplication support, SnapDrive 5.0 or higher support for iSCSI with vFiler instances, SnapVault additions, and SnapLock support.

Some of the potential use cases for MultiStore include file services consolidation (allows you to preserve file server identification onto separate vFiler instances), data migration, and disaster recovery. You might also use MultiStore if you needed support for multiple Active Directory domains with CIFS.

UPDATE: Apparently, my recollection of the presenters’ information was incorrect, and FTP is not a protocol supported with vFilers. I’ve updated the article accordingly.

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What If Hypervisors Shared a File System?

Tuesday, February 10, 2009 in Storage, Virtualization by slowe | 20 comments

This is more of a “thinking out loud” sort of post, so bear with me. It doesn’t necessarily have a point, other than to prompt readers to start thinking.

VMware has VMFS. Microsoft has CSV, or will in Windows Server 2008 R2. (Does XenServer have a clustered file system? I don’t know.) What would happen if all the major hypervisors had a clustered file system in common? How would that impact virtualization?

I’ve written before about how cloud computing needs standards in order to really see broad adoption. People like to point to stuff like OVF, and that’s great, but what about brass tacks kind of stuff like file systems? Would a clustered file system that worked equally well with Hyper-V, ESX, and XenServer make any difference? What sort of flexibility or interoperability might it bring?

And, for further thought, what benefit would there be for that same clustered file system to be accessible from the guest operating systems running in virtual machines on these various platforms?

I’d love to hear everyone’s thoughts.

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Free Sanbolic Licenses for Windows Server 2008 R2 Beta Users

Wednesday, January 14, 2009 in Microsoft, Storage, Virtualization by slowe | No comments

Here’s an announcement that is exclusive to readers of my site: I have learned that Sanbolic—the company behind Melio FS and other products about which I’ve blogged before, including very recently—plans to offer free licenses of La Scala and Melio FS to beta testers of Windows Server 2008 R2.

That’s right: free licenses for the La Scala volume manager and Melio FS shared file system for Windows Server 2008 R2 beta testers. The licenses will be good only during the beta period, and will allow beta testers to directly compare Melio FS to Microsoft’s Cluster Shared Volumes (CSV). Both products are an enabling technology for the Live Migration functionality that Microsoft is planning on including with the next version of Hyper-V. Sanbolic is convinced that Melio FS is far superior to CSV, and wants beta testers to have the opportunity to see that for themselves. It’s a bold move, in my opinion, and I have to applaud them for it. Let your product stand or fall on its own merits, I’ve said before, and that’s exactly what Sanbolic is doing.

Expect the official announcement on the free La Scala and Melio FS licenses to show up from Sanbolic in the next few weeks.

In the meantime, feel free to review these other articles I’ve written about Sanbolic, Melio FS, La Scala, and/or Kayo FS:

UPDATE: Sanbolic issued the official press release today (April 2, 2009; no direct link available for the press release), making the announcement about the free evaluation version of Melio FS for Windows Server 2008 R2 beta users. Visit the Sanbolic web site for more information.

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VMware ESX and ESXi SAN I/O Issue

Monday, January 12, 2009 in Storage, Virtualization by slowe | 2 comments

Via this Twitter post, I learned that VMware has posted a new KB article about a SAN I/O failure that can occur with VMware ESX and ESXi 3.5 Update 3. If you are using VMware ESX or ESXi 3.5 Update 3, please be sure to read the KB article and stay tuned here for additional updates. I will update this post when I get more information.

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Sanbolic Optimizes Melio FS, Adds Virtualization Support

Friday, January 9, 2009 in Microsoft, Storage, Virtualization by slowe | No comments

Back in June, I wrote about Sanbolic and Melio FS as a workaround for the “one-VM-per-LUN” limitation that Hyper-V’s Quick Migration imposes. By running Melio FS on a Windows Server 2008 Hyper-V host, users could put multiple VMs in the same LUN and still use Quick Migration. At the same time, Sanbolic was also announcing that they were supporting the use of Melio FS, their clustered file system, inside Windows Server-based VMs running on VMware ESX.

In September, Sanbolic announced that they would be supporting Melio FS in VMs running on Hyper-V. This expanded their clustered file system support so that VMs running on either VMware ESX or Hyper-V could use Melio FS for shared storage access.

Yesterday, Sanbolic added support for running Melio FS in guests on Citrix XenServer, bringing support for their Windows-based clustered file system to VMs on all three major virtualization platforms. In addition, yesterday’s announcement also indicated that Sanbolic was adding support for the Windows Server 2008 R2 beta, and that Melio FS had been optimized for block objects like virtual disk files and databases. The full press release is available here as a PDF file.

Clearly, Sanbolic wants to protect the value of Melio FS as Microsoft prepares to enter the clustered file system market with Cluster Shared Volumes (CSV), included in the R2 beta. It’s unclear to me whether CSV is going to be limited to virtualization only, addressing the “one-VM-per-LUN” issue, or whether Microsoft will also support CSV in other applications. By optimizing Melio FS for shared access to objects like virtual disk files and by extending support to run Melio FS in VMs on all the major platforms, Sanbolic hopes to establish Melio FS as a “de facto” standard in Windows-based clustered file systems.

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Storage Short Take #4

Tuesday, December 2, 2008 in Storage by slowe | 2 comments

Last week I provided a list of virtualization-related items that had made their way into my Inbox in some form or another; today I’ll share storage-related items with you in Storage Short Take #4! This post will also be cross-published to the Storage Monkeys Blogs.

  • Stephen Foskett has a nice round-up of some of the storage-related changes available to users in VMWare ESX 3.5 Update 3. Of particular note to many users is the VMDK Recovery Tool. Oh, and be sure to have a look at Stephen’s list of top 10 innovative enterprise storage hardware products. He invited me to participate in creating the list, but I just didn’t feel like I would have been able to contribute anything genuinely useful. Storage is an area I enjoy, but I don’t think I’ve risen to the ranks of “storage guru” just yet.
  • And in the area of top 10 storage lists, Marc Farley shares his list of top 10 network storage innovations as well. I’ll have to be honest—I recognize more of these products than I did ones on Stephen’s list.
  • Robin Harris of StorageMojo provides some great insight into the details behind EMC’s Atmos cloud storage product. I won’t even begin to try to summarize some of that information here as it’s way past my level, but it’s fascinating reading. What’s also interesting to me is that EMC chose to require users to use an API to really interact with the Atmos (more detailed reasons why provided here by Chad Sakac), while child company VMware is seeking to prevent users from having to modify their applications to take advantage of “the cloud.” I don’t necessarily see a conflict between these two approaches as they are seeking to address two different issues. Actually, I see similarities between EMC’s Atmos approach and Microsoft’s Azure approach, both which require retooling applications to take advantage of the new technology.
  • Speaking of Chad, here’s a recent post on how to add storage to the Celerra Virtual Appliance.
  • Andy Leonard took up a concern about NetApp deduplication and volume size limits a while back. The basic gist of the concern is that in its current incarnation, NetApp deduplication limits the size of the volume that can be deduplicated. If the size of the volume ever exceeds that limit, it can’t be deduplicated—even if the volume is subsequently resized back within the limit. With that in mind, users must actively track deduplication space savings so that, in the event they need to undo the deduplication, they don’t inadvertently lose the ability to deduplicate because they exceeded the size limit. Although Larry Freeman aka “Dr Dedupe” responded in the comments to Andy’s post, I don’t think that he actually addressed the problem Andy was trying to state. Although the logical data size can grow to 16TB within a deduplicated volume, you’ll still need to watch deduplication space savings if you think you might need to undo the deduplication for whatever reason. Otherwise, you could exceed the volume size limitations and lose the ability to deduplicate that volume.
  • And while we are on the subject of NetApp, a blog post by Beth Pariseau from earlier in the year recently caught my attention; it was in regards to NetApp Snapshots in LUN environments. I’ve discussed a little bit of this before in my post about managing space requirements with LUNs. The basic question: how much additional space is recommended—or required—when using Snapshots and LUNs? Before the advent of Snapshot auto-delete and volume autogrow, the mantra from NetApp was “2x + delta”—two times the size of the LUN plus changes. With the addition of these features, deduplication, and additional thin provisioning functionality, NetApp has now moved their focus to “1x + Delta”—the size of the LUN plus space needed for changes. It’s not surprising to me that there is confusion in this area, as NetApp themselves has worked so hard to preach “2x + Delta” and now has to go back and change their message. Bottom line: You’re going to need additional space for storing Snapshots of your LUNs, and the real amount is determined by your change rate, how many Snapshots you will keep, and for how long you will keep them. 20% might be enough, or you might need 120%. It all depends upon your applications and your business needs.
  • If you’re into Solaris ZFS, be sure to have a look at this NFS performance white paper by Sun. It provides some good details on recent changes to how NFS exports are implemented in conjunction with ZFS.

That’s it for this time around, but feel free to share any interesting links and your thoughts on them in the comments!

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4198: Hyper-V on NetApp Deep Dive

Monday, December 1, 2008 in Microsoft, Storage, Virtualization by slowe | 2 comments

This session provided information on running Hyper-V with NetApp storage. The first part of the session focused primarily on Hyper-V basics, such as VHD types (dynamically-expanding, fixed-size, passthrough, differencing), partition alignment (which can only be guaranteed with fixed-size VHDs, by the way), SCVMM 2008, Windows Failover Clustering support, and such. If you’re interested in details on those topics, I suggest you have a look at my coverage of Microsoft Tech-Ed 2008 back in the summer.

The second part of the session delved into some NetApp-specific information:

  • NetApp has a PVR-only tool called HyperVIBE that helps to coordinate storage array Snapshots with the hypervisor, providing VSS integration to quiesce the VMs before taking a Snapshot on the NetApp array. This is only supported on Server Core and requires a special release of SnapDrive 6.0. (It’s only available via PVR, so don’t go searching the NetApp web site for a free download.)
  • The various members of the SnapManager family—SnapManager for SQL, SnapManager for Exchange, and SnapManager for Sharepoint—are all fully supported on Hyper-V, but only for iSCSI LUNs.
  • NetApp SnapDrive 6.x is supported both on Hyper-V hosts as well as guest VMs. On the parent partition, it can manage both Fibre Channel LUNs and iSCSI LUNs; on a child partition, it can only manage iSCSI LUNs.
  • Version 5.x of the Host Utilities Kit is strongly recommended for use with Hyper-V, and supports Fibre Channel, iSCSI, and mixed connections. It runs on either the parent or child partition, although it seems to me that it would only make sense to run it on the parent partition.
  • Data ONTAP DSM 3.2R1 is the supported and recommended DSM for MPIO support with Hyper-V. On the parent partition, it supports and manages Fibre Channel, iSCSI, and mixed paths, but in a child partition it only supports iSCSI paths. It’s also only supported in child partitions running a server OS (so no Windows XP or Windows Vista support in child partitions).

For more information, readers can refer to TR-3701 and TR-3702. Note that updated versions of TR-3702 are expected to be released in the coming months to address additional product integrations.

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Virtualization Short Take #23

Wednesday, November 19, 2008 in Virtualization by slowe | No comments

A short while ago, I had a colleague in the blogging industry ask me if the reason I was writing “Short Takes” was because I was too busy to write in-depth articles. At the time, I told this colleague no, but now I’m wondering if I should change that answer…

In any event, here’s my list of links and tidbits that I found interesting, amusing, or useful over the last week or so. Enjoy!

  • Eric Sloof of NTPRO.NL points out that VMware has updated their best practices to “allow” the placement of VM swap files on NFS, rather than recommending VMFS. Does anyone have a link to the VMware KB article with those updated recommendations?
  • Edward Haletky points out a process for performing “secure P2V” operations. Because the P2V process generally involves network communications with VirtualCenter and/or the VMware ESX Service Console, a straight P2V process would cross security boundaries. Edward’s phased approach helps with that issue.
  • Into PowerShell, but finding the process of modifying Offload Policies too difficult? This should help out significantly.
  • Expanding upon some earlier work, Rick has added “Resolution Paths” to common network issues and common licensing issues. Excellent work!
  • Leo provides some good information on monitoring VI3 with Zenoss.
  • Via Alessandro and Ben, I learned about the HVRemote tool for automating the configuration steps for enabling remote management of Hyper-V. HVRemote was created by John Howard and more information is available here.
  • Symbolik shares his experience in troubleshooting a PSoD (Purple Screen of Death) with VMware ESX. In his case, the issue turned out to be related to NICs, but it’s nice to see that he was able to zero in on the issue and get it resolved.
  • Larger installations with lots of LUNs and an active/active SAN may find this script published by Duncan very helpful. The problem that this script addressed underscores the need for robust multipathing support in VMware ESX such as that which will be allowed via the new vStorage APIs.
  • Need more information on Enhanced VMotion Compatibility (EVC)? Both Gabe and Rich have recently tackled the issue on their own blogs. If you’re wondering what EVC is, the short answer is that it’s a way to automate this process in a supported fashion.

That’s it for this time around. Thanks for reading!

UPDATE: Eric Sloof responded about the updated recommendations regarding VM swap files. The new information was disclosed in session TA2784 at VMworld 2008. See slide 38. Thanks for the information, Eric!

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