you can run the scan on a snapshot to determine if you need to run an mbralign.  I don't think you run the align while the vm is up - I think at best you would only get a crash consistent copy that was valid as of the time of the beginning of the align and have to take an outage to reboot the vm off the aligned vmdk.

Jack

On 8/26/2011 8:10 PM, Alexander Griesser wrote:
Re: Sources of unaligned IO other that Vmware? - pw.over_limit persists

I don’t think that this will work – but I’m going to try that out on Monday unless the OP clarifies that he didn’t mean it like that J

 

Running mbralign is a long-lasting process, especially for really big vmdks, but we always worked around that by having small „system“ or „boot“ vmdks and added additional disk space by adding additional vmdks which we initialized with GPT right from the start.

 

Later on, we created default templates with already aligned but empty disks which also works a treat.

 

Bye,

Alex

 

Von: toasters-bounces@teaparty.net [mailto:toasters-bounces@teaparty.net] Im Auftrag von Fletcher Cocquyt
Gesendet: Samstag, 27. August 2011 01:47
An: Chris Muellner; Eugene Vilensky
Cc: toasters@teaparty.net
Betreff: Re: Sources of unaligned IO other that Vmware? - pw.over_limitpersists

 

Holy Shnikies – does this actually work? And is it supported? (running mbralign with a snapshot, then (presumably) deleting the snapshot to merge the delta files back into the newly aligned vmdk – brilliant!)
We took downtime on all VMs to align them – the big ones took hours...even with 10gig networking – can’t believe I had not seen mention of this before.
How do you deal with the linux VMs which need boot file modification post alignment to (re)boot successfully?

FWIW, all our VMs are aligned now – we run a daily mbrscan report to pickup any stray misaligned vmdk files (usually they are virtual appliances)



On 8/26/11 1:05 PM, "Chris Muellner" <chris@northlandusa.com> wrote:

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.


--
Fletcher Cocquyt
Principal Engineer
Information Resources and Technology (IRT)
Stanford University School of Medicine

http://vmadmin.info 



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