One of the labs we’re creating for the upcoming Omaha-Area VMUG is SRM.  It is posing some interesting challenges.  The biggest challenge is figuring out how to best provide a lab to 15 pairs of people without creating 30 sites.  We will cut some corners on that issue by having the instructor perform some of the core tasks like pairing sites and configuring the arrays.  This leaves users to work directly with the Protection Groups and Recovery Plans, which is where people need to pay the most attention anyways.

The other interesting challenge for us is one you find each time you setup SRM for a different array than you’ve done in the past.  In this case it was setting it up to use a CX4 using MirrorView. 

For those who aren’t familiar with why this is a big deal, let me explain.  SRM ties directly into the storage array in order to affect the status of the replication and to create LUN level snapshots during failover tests.  In order to do this, SRM uses a Site Recovery Adapter (SRA) to talk to the array.  The twist is that the storage vendor is responsible for creating the SRA for each array that SRM supports.  The difficulty lies in the different implementations and prerequisites each vendor has for their SRAs.

Here are a few things I discovered about using the EMC MirrorView SRA:

• Not only do you need to install the SRA on the SRM server, but you also need to install EMC’s Solutions Enabler.  As I understand it, Solutions Enabler is the foundation for software that needs to talk to the CX4 storage processors (somewhat analogous to the .NET framework).  EMC folks correct me where I might be wrong.
• After creating the remote mirror of the LUN, you need to create a snapshot of the destination LUN (at the recovery site).  The name you give this snapshot must include the substring “VMWARE_SRM_SNAP”.  Make sure reserve LUNs are created for this snapshot, which should be done when using the “Configure SnapView Snapshots” wizard.  The SRA will NOT create the snapshot on the fly for you like some SRAs will.
• A Consistency Group is not necessary unless your protected VMs cross multiple LUNs or you want multiple LUNs in a single Protection Group

Useful links:

EMC_MirrorView_Adapter_for_VMware_SRM_Release_Notes_v1.4

I wanted to start my series of blog posts about the Omaha-Area VMUG lab infrastructure with the base of the infrastructure (or any virtual infrastructure): the storage.

We were lucky enough to work out a deal with EMC to let us borrow a couple of Clariion arrays.  Specifically they are CX4-120 arrays.  Not that impressive you say?  What if I told you they were configured with six 200GB Enterprise Flash Drives (EFD) (see the first photo)?  Now do I have your attention?

Anecdote: I had an EMC sales rep ask me why I don’t have the face plates on our devices.  I told him it was because I care more about geeking out about the devices than about marketing the devices.

To summarize, we have two CX4-120s with about 1TB of usable EFD storage.  Both arrays have EMC’s mirroring software, MirrorView enabled so we can replicate between the two arrays (for the SRM lab).

The array consists of three distinct parts: the standby power supplies (SPS), which act as power distribution, but also contain batteries to allow for a graceful shutdown of the array should a loss of power occur; the storage processor enclosure (SPE), which contains the storage processors (SPs) (some may call these the controllers) and I/O modules (including fiber and iSCSI connectivity); and the disk array enclosure (DAE), which contains up to 15 drives (the first five of which contain the operating system for the array).  More technical details can be found here.

I would love to post a comparison of the HP EVAs that my company is used to dealing with (see the next picture with an EVA below and above the CX4 in our rack), but I have to admit to not knowing enough about either array to do such a comparison justice.  Not to mention the fact that I’d be comparing an array with EFDs to one with mostly 10k disks.  So, I’ll just discuss my experiences with the CX4 for what they are, not as a comparison to the EVA (sorry EMC).

The racking of the equipment wasn’t terribly complicated and was easily figured out using the enclosed quick start guide, though there is a mess of cables required to get all the pieces properly connected (see the next photo).

At this stage, we have only racked, cabled and powered on these two arrays, so I can’t judge performance yet.  That’s it for now, but keep a look out for a future post where I will hopefully be gushing on how awesome performance is on this array.