That's right. I blogged on it a bit here:
http://communities.netapp.com/community/netapp-blogs/getvirtical/blog/20 11/05/13/new-vmdk-misalignment-detection-tools-in-data-ontap-735-and-802
Share and enjoy!
Peter
From: Chris Muellner [mailto:chris@northlandusa.com] Sent: Friday, August 26, 2011 1:05 PM To: Eugene Vilensky Cc: toasters@teaparty.net Subject: RE: Sources of unaligned IO other that Vmware? - pw.over_limitpersists
"Will easily queryable stats about misaligned VMDKs on NFS ever be available?"
It already is actually. Download the latest version of the ESX Host Utility Kit and use the mbralign utility that's included with it. It can be run from either the VMware hosts themselves or from a Linux/Unix server with mount access. If you take a NetApp snapshot of the datastore then you can run the mbralign scan against the snapshotted -flat.vmdk(s) without having to power off the virtual machines.
Also, some VMware align/misalignment statistics are included in the output of nfsstat -d in version 7.3.5.1 or later. I may be slightly off on the OnTap release version...
From: toasters-bounces@teaparty.net [mailto:toasters-bounces@teaparty.net] On Behalf Of Eugene Vilensky Sent: Friday, August 26, 2011 2:39 PM Cc: toasters@teaparty.net Subject: Re: Sources of unaligned IO other that Vmware? - pw.over_limit persists
On Fri, Aug 26, 2011 at 11:34 AM, Jeff Mohler speedtoys.racing@gmail.com wrote:
"By the way, from ONTAP 8.0.1+, you can directly check alignment with the "lun show -v" command:"
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Gotta be careful here, this only works on the -direct- lun.
This will not tell you how healthy any underlying virtual filesystems within the LUN may or may not be, only the high level direct LUN itself.
Will easily queryable stats about misaligned VMDKs on NFS ever be available? Without mounting the datastores on Linux and checking with fdisk...