I have been asked this question multiple times, so I thought I would document the answer and the reasons why. The question is: I have an IBM SVC running code version 4.3 and due to hardware or change limitations I am not going to upgrade it to version 5 or 6 of the SVC firmware. Can I still buy a Storwize V7000 and virtualize it behind the SVC ?
The answer is no you cannot.
Why not? Well first up it doesn’t work…. Let me show you why:
The ability for the SVC to recognize a backend storage controller is based on the SCSI Vendor description reported during SAN discovery. Because each device ordinarily reports a unique identifier, the SVC can determine how to handle that device from a multi-path perspective. If the SVC discovers a device it does not recognise, it will not know how to manage the SAN paths. In the example below, the SVC can see three external storage controllers clearly identifiable by the vendor_id and the product_id (which both get reported by the storage controller itself).
IBM_2076:STG_V7000:admin>svcinfo lscontroller id controller_name ctrl_s/n vendor_id product_id_low 0 XIV 0EB00000 IBM 2810XIV- 1 DS4700 IBM 1814 2 DS8000 75DC711FFFF IBM 2107900 3 DS6800 1357580FFFF IBM 1750500
The SVC hardware support matrix for SVC firmware version 4.3 can be found here:
It does not list Storwize V7000.
So I did a test, presenting a Storwize V7000 to an SVC cluster running SVC 4.3 code.
The result was unsurprising, using the command svcinfo lsfabric showed the V7000 as ‘unknown’:
Compare this to what it shows when it detects a DS4800:
The simple solution? Upgrade your IBM SVC code to release 126.96.36.199 or above. The 188.8.131.52 release come out September 2010. Considering the Storwize V7000 was announced at roughly the same time (October 2010), this makes perfect sense.
If the only reason you are running 4.3 code is that you are using 2145-4F2 nodes, please note the following: These nodes were first released in June 2003, over eight years ago. IBM are not going to support that hardware past December 2011 (details here) or the software (release 4.3) past April 2012 (details here). So we are talking about a hardware/software combination that will soon be unsupported. Upgrading to newer node hardware will yield significant performance gains while upgrading to newer software will yield significant software functionality. It’s a win/win.
If you are migrating from SVC 2145-4F2 nodes to Storwize V7000, please consider using options such as:
- Migrate your SVC VDisks to image mode and then remap them to the Storwize V7000.
- For VMware users, use Storage vMotion.
- Consider other migration software such as LVM mirroring, Softek or Veritas Volume Manager.