Comments on: EMC Celerra Optimizations for VMware on NFS

By: paul

paul — Fri, 01 Apr 2011 19:48:53 +0000

write performance of Celerra’s decreases when replicator or snapshots are used. The snapsure technology which is used for both will slow write performance greatly when used. If you get 95-105MB/s write performance initially, you will see this drop to a fraction (as low as 15 or lower MB/s) when writing files to the Celerra. An undocumented but extermely discouraging “feature” of Celerra.

By: Jim Nickel

Jim Nickel — Wed, 23 Mar 2011 19:10:48 +0000

Marge,

Probably the easiest way to see alignment is to use this:

http://read.virtualizeplanet.com/?p=366

vDisk Informer – free product, works great.

Once a machine is aligned, it will stay aligned (we are talking about partition alignment of the guest OS here).

Any machine created with Windows 2008 will automatically be aligned correctly.

Any machine created with Windows 2003 will NOT be correctly aligned. You must correct this – best option is to create an aligned template and then just create more VM`s from that template – then they will all be aligned.

Jim

By: Marge

Marge — Wed, 16 Feb 2011 14:22:14 +0000

How can you determine if your “virtual machine disk/application partitions have been properly aligned?”

How can you properly align them to start with?

How do you keep them aligned?

By: Michael

Michael — Fri, 26 Feb 2010 18:56:53 +0000

I have done considerable research on this and I have concluded that there is no performance benefit from disk alignment in the GOS if the underlying storage is NFS (block based yes). This is because NFS separates the block based storage from the GOS and exposes a single disk to the VM. There is no performance benefit from aligning a single disk volume.

That being said, you should still align the GOS as it makes the VM vMotion “compatible” with block-based storage without degrading performance. And it is *much* easier to align in the beginning instead of retrofitting.

By: Matt Mancini

Matt Mancini — Mon, 08 Feb 2010 17:22:11 +0000

We are just starting down the path of comparing our Celerra to NetApp and this was some helpful information to get us started out!

thanks..

By: karl

karl — Tue, 02 Feb 2010 09:16:52 +0000

Hi,

do you think that these Celerra Optimizations will work with XenServer (instead of ESX) ?

Thanks

By: ron

ron — Tue, 02 Feb 2010 06:11:14 +0000

Belay that capt. i think I found what I needed, unless you know of something better, http://www.emc.com/collateral/hardware/white-papers/h1416-emc-clariion-intgtn-vmware-wp.pdf

Ron

By: ron

ron — Tue, 02 Feb 2010 06:07:04 +0000

Scott,

Any chance you know of any docs for using ESX 3.5 (or vSphere) and an AX-4? For direct attached storage, or is it just dead simple

We just got an NS120 (not even powered on yet) and no one feels comfortable running VM’s off of NFS, and I cant sway them, so we’re also on the cusp of getting the AX-4 probably, so if you know of anything I appreciate it.

Thanks very much

Ron

By: slowe

slowe — Tue, 02 Feb 2010 03:39:52 +0000

Derek,

The EMC CLARiiON-VMware integration white paper also recommends an 8K allocation unit size unless the application or vendor recommends otherwise. See page 27 of this document:

http://www.emc.com/collateral/hardware/white-papers/h1416-emc-clariion-intgtn-vmware-wp.pdf

I hope this helps!

By: Derek

Derek — Tue, 02 Feb 2010 03:11:00 +0000

Does the 8K NTFS block size also apply to traditional VMDKs hosted on SAN Fibre Channel storage? Or is that setting unique to NFS hosted VMDKs?