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:
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
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