UCS with vsphere to BFS on IBM XIV

[dani_bosch]

Hello,

It seems that IBM XIV storage has a limitation around the minimum LUN size, which appears to be 17 GB. Taking into consideration that one of the added values of UCS is the boot from SAN using the service profiles, and that most of the UCS implementations are based on VMware (the OS of which, ESXi barely needs 300 MB of installation), that means one has to underutilize 17GB LUNs for ESXi booting, which might be a waste of money. I was wondering whether anyone here found the same issue in their customers and whether does this also happen in other disk arrays (EMC Symmetrix for instance), or only in IBM XIV.

Thanks a lot,

[dani_bosch]

No inputs about this?

[dani_bosch]

Nothing at all?

[Robert Burns · Accepted solution]

Dani,

That really sounds silly about a 17GB min. configured LUN size but looks true:

http://storagemojo.com/2011/11/01/14-things-to-know-about-xiv/

I've never heard of any such min. LUN size anywhere near that size on any NetApp or EMC array.

As this is an IBM array issue, I'd suggest confirming this with IBM.

Regards,

Robert

[grinks311 · Accepted solution]

Dani,

Also check out this blog.  I thought you maybe able to get around this by creating a thin provisioned pool, and then creating multiple LUN's for your ESXi hosts in that pool, however, it looks like on the first write to that LUN it is going to attempt to take the 17GB min LUN size.

I think you maybe stuck with the 17GB LUN per host.  I will say that some other storage vendors do not have this 'limitation', this is due to the XIV architecture.

http://patrickv.info/wordpress/2009/07/ibm-xiv-thin-provisioning/

Regards,

Jeremy

[dani_bosch]

Thanks guys