The Compaq MSA1000 has been off VMware's Hardware Compatibility list since vSphere 4, with the last supported release being ESX 3.5 U5 (source - http://www.vmware.com/resources/compatibility .)
Fig. 1 – MSA1000 Supported Releases
Now, just because the MSA 1000 is not supported with vSphere 5, does not mean that it will not work with vSphere 5 – and indeed the MSA 1000 does work with vSphere 5. The below image is taken from an ESXi 5.0 host – the datastores with Device identified as "COMPAQ Fibre Channel Disk" are from the MSA 1000.
Fig. 2 - Storage > Configuration > Datastores View
One thing you need to take into account when migrating from VMware Virtual Infrastructure 3 (VI 3) to vSphere 5, is that datastores formatted with a file system of VMFS 3.21 cannot be seen by ESXi 5.0 hosts (ESX 3.0.0 is provided with the initial VMFS 3 release of VMFS 3.21, ESX 3.5.0 with VMFS 3.31, ESX 4.0 with VMFS 3.33, ESX 4.1 with VMFS 3.46, ESXi 5.0 with VMFS 5.54 – see VMware KB 1005325.) This means that any datastores created by ESX 3.0 hosts will not be visible when presented to an ESXi 5.0 host, whereas datastores created by an ESX 3.5 host will be visible (I have not seen this documented by VMware, only evidenced in a real world situation - so do not totally take my word on this!)
Fig. 3 – Datastore properties showing a datastore formatted with VMFS 3.21
The particular migration behind this post involved a migration from a Compaq MSA 1000 to HP P2000 G3 MSA, and upgrade/rebuild of VMware VI 3 as VMware vSphere 5. The Implementation Plan included the following steps:
1) Evacuate all VM guests from the ESX 3.5 U5 host to be rebuilt as ESXi 5.0, shutdown host and remove from the 2.5 U6 Virtual Center.
2) Install new 8 GB FC HBAs alongside the existing 4 GB FC HBAs into the HP ProLiant DL380 G5 host server.
3) Check BIOS settings for Static High Performance Settting enabled, No-Execute Memory Protection enabled, and Hardware Assisted Virtualization enabled.
4) Upgrade host server firmware.
5) Install ESXi 5.0 and configure host.
6) Install vSphere 5 vCentre Server with Update Manager on new Windows 2008 R2 Server.
7) Use vCenter Update Manager to apply critical patches
8) Use vCenter Update Manager to apply "HP P2000 Software Plug-in for VMware VAAI vSphere 5.0" *Google the terms inbetween the quotation marks to find the download page with installation instructions – current latest version at the time of writing was 2.00 (28 Oct 2011) and file name hp_vaaip_p2000_p210.zip
9) Install "HP ESXi Offline Bundle for VMware ESXi 5.0" *Google the terms inbetween the quotation marks to find the download page with installation instructions – current latest version at the time of writing was 1.1 (16 Dec 2011) and file name hp-esxi5.0uX-bundle-1.1-37.zip
10) Configure FC SAN environment such that ESXi 5.0 host can see old MSA 1000 LUNs and new HP P2000 G3 LUNs.
11) Unregister guests from ESX 3.5 U5 host, register with ESXi 5.0 host, and perform storage vMotion from MSA 1000 FC SAN to HP P2000 G3 FC SAN.
12) Repeat appropriate steps for subsequent host servers to be upgraded.
Note 1: For guests on VMFS 3.21 LUNs, these were first migrated to a VMFS 3.31 LUN across an ESX 3.5 U5 host.
Note 2: Live Storage vMotion from VMFS 3 LUNs on an MSA 1000, to VMFS 5 LUNs on a HP P2000 G3, is perfectly possible – they worked fine!
Note 3: VMware tools can be upgraded directly from VI 3 to vSphere 5.
I would not recommend running live production VMware vSphere 5 guest machines on top of a Compaq MSA1000 SAN. It will work, any problem though and VMware support are well within their rights to turn around and say "this is unsupported in vSphere."