Which is not possible anymore now that ESX is dying and the whole world migrates to ESXi.

Another thing to consider when using mbralign is that it kills most Linux bootloaders, so be careful – never had a broken Windows VM after running mbralign on its vmdk, but almost ever manage to break the Linux bootloader with it, so prepare for breakage and have a rescue cd at hand with which you can reinstall the bootloader afterwards.

Bye,

Alex

Von: toasters-bounces@teaparty.net [mailto:toasters-bounces@teaparty.net] Im Auftrag von Jack Lyons
Gesendet: Samstag, 27. August 2011 01:26
An: toasters@teaparty.net
Betreff: Re: Sources of unaligned IO other that Vmware? - pw.over_limitpersists

the best thing about mbralign is that it will fix misaligned vmdk's too (with certain caveats) on any vendor's storage array.

it has been awhile since I ran the utility, but it works better if you run it on the esx host that "owns" the VM

Jack

On 8/26/2011 4:05 PM, Chris Muellner wrote:

“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:"

---

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...

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