Our recent chat on the benefits of using EqualLogic iSCSI storage for virtualization solutions like VMware and XenServer was great. We had a longtime EqualLogic guy - Tim Sherback - and quite a few expert users who talked in detail about all of the features of EqualLogic that work so well with VMware and XenServer. Things like thin-provisioning, simplified management, and ease of expansion were mentioned. The most compelling aspect to me is the deep integration that has been done with the Auto Snapshot Manager for VMware, Auto Replication with VMware Site Recovery Manager, and the EqualLogic adapter for XenServer 5.0 Dell Edition. In each case the virtualization software (either VMware of XenServer) is able to use the hardware features of an EqualLogic array to accomplish what would have been done in software. For example you can use the snapshot feature of the array to make a VM snapshot. Check out the chat transcript for more details and also check out the demo vidoes to see it in action.

The other really great aspect of the chat was a discussion around when to pick EqualLogic or MD3000i. There was lots of info which should help anybody trying to decide which to use. I recommend that you read the transcript to get the details - this part of the chat is towards the end if you want to just skip right to it.

Todd

To follow up on the Hyper-V Server install video from last week, I added a new page to delltechcenter.com that shows how to configure a connection to an iSCSI storage array for Hyper-V Server. With a full Windows Server 2008 installation there is a GUI tool in Administrative Tools called iSCSI Initiator that is used to configure and manage these connections. Windows Server 2008 Core and Hyper-V Server do not have a GUI, so a command-line version called iscsicli.exe must be used.

The page that I added shows how to create a simple iSCSI connection by first enabling the iSCSI Initiator service with the sc (service console) command, then using iscsicli.exe to map the connection to the target iSCSI LUN, and then using diskpart.exe to do the partitioning and formatting. It's not as bad as it sounds, and is pretty straightforward once you know the commands.

To get an MPIO-type connection set up is only a little bit more involved. There is a script that I found in a Microsoft TechNet forum that is an example of how to do an MPIO connection to an MD3000i using iscsicli.exe. You can also use a GUI-based tool called Storage Explorer that is included with Windows Server 2008 to connect remotely to the Hyper-V server and create additional connections. (It doesn't see anything until you have used iscsicli.exe to get the initial connection.)

Todd

The VMware VI Team Blog recently had an entry announcing that Storage VMotion is now supported with iSCSI. Although many of you may not have known, until this announcement Storage Vmotion was only supported with fibre channel storage. I did a video demo of Storage VMotion a few months ago when it came out. The funny story is that I actually had to redo the video after recording it the first time because initially I had used an the iSCSI based PowerVault MD3000i as the source. When I found out that iSCSI wasn't supported, I had to re-record it - no big deal - but it made me really appreciate this announcement of support. This really makes Storage VMotion much more compelling as you can use it to migrate your VMs between fibre and iSCSI without interruption.

Todd

After spending the last few weeks looking into which server to choose for virtualization, a natural next question is - What should I use for storage? I think that the answer here may be easier in some ways, but more complicated in other ways.

Mark Farley, on the InsideIT blog, highlighted a recent video by Darren Thomas, General Manager of Storage - aka Chief Storage Guy - here at Dell, that focuses on how storage virtualization works well with server virtualization. Just as VMs are able to use live migration to move from one physical server to another, virtualized storage can move those same VMs from one storage array to another. The result is that you have a tremendous amount of flexibility and availability.

There are three major categories for storage: local, iSCSI, and Fibre Channel. There are lots of choices within these, but I think that when deciding what to use to support your virtualization servers this is the best starting organization. If you are going to only have one virtualization server (or one per location) then local storage will work just great. If you already have an existing fibre channel SAN and existing expertise to manage it, then fibre may be the best solution for your virtualization server farm. Everybody else should probably take a really hard look at iSCSI.

Within the iSCSI category at Dell we have three areas to pick from: PowerVault MD3000i, Dell EqualLogic PS Series, and Dell | EMC AX and CX iSCSI arrays. I think that the decision here also breaks down very similar to how we arrived at the type of storage. For smaller deployments or those that do not need array level features like replication the PowerVault MD3000i (with an attractive entry-level price) is a good choice. For customers that already have some Dell|EMC fibre channel or iSCSI it might be a good idea to extend this environment with additional iSCSI for your virtualization needs. I think that the Dell|EqualLogic PS series is a strong contender for all other solutions.

Of course it's really a bit more complicated than this, but this is the way that I frame up a conversation around storage for virtualization solutions.

Todd