Comments on: Virtualization Short Take #22

By: Dejan Ilic

Dejan Ilic — Wed, 12 Nov 2008 15:46:32 +0000

You have smaller disksolution vendors doing the “spin-down-unused-disks” already (notably NexSan with MAID). Check out http://www.nexsan.com/solutions/energysavings/

But I wonder how that would work with consolidated systems that require lots of IOPS. You would probably have to use storage tiering (on block level) to be able to spin down disks at all.

By: slowe

slowe — Wed, 12 Nov 2008 04:28:02 +0000

Andy,

Yeah, I knew you were joking, but it would be nice to have a storage vendor pay more attention to the power all those spinning drives suck down.

By: slowe

slowe — Wed, 12 Nov 2008 04:25:33 +0000

Dejan,

Great question! From what I’ve been able to gather, the Service Console helps to manage the VMkernel NFS connections, so increasing the memory for the Service Console provides more RAM for managing those NFS connections. In some cases, we’ve had VMware Support tell our customers that a lack of memory in the Service Console is the source of some of the NFS strangeness they might be experiencing. After having several customers told by VMware Support to bump the Service Console memory to 800MB, we decided to incorporate this into our standard configuration for NFS installations.

By: Dejan

Dejan — Tue, 11 Nov 2008 18:13:59 +0000

Why do you recommend increasing Service Console Memory when using NFS?
Could you explain the technical reason? Is there any kind om extra buffers or something like that?

By: Andy Leonard

Andy Leonard — Tue, 11 Nov 2008 17:39:54 +0000

Thanks for the link – the comment about spinning down the idle drives was tongue in cheek – but I think you knew that already. Mostly, I was pointing out (obliquely) that my storage systems, while also shared with many other systems, draw far more power than my VMware machines.

But, hey, when DPM is ready, if it works for us, we’ll be using it. And I also wouldn’t be surprised if one of the big storage vendors someday had something that integrated with DPM… but I agree with your advice not to hold my breath.