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Formatting a disk in Hyper-V is slow
I have a 9TB LUN which I attached to a Hyper-V host and I want to format this LUN to become a CSV (cluster shared volume), but the formatting takes hours. The LUN resides on a Dell EMC Unity 450F (all flash). Does anyone know how to speed things up a bit?
Mich
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April 3rd, 2018 19:00
Thanks for the extra information.
Slow format's can be caused by TRIM/UNmap being enabled by default on Windows 2012 and above. Although you don't mention the OS version you are running.
The issue arises when a format starts on the LUN, trim identifies space to reclaim and begins attempting to unmap/trim the allocated tracks. This can also cause performance issues to the array by flooding it with unmap commands.
To disable use the command: fsutil behaviour set DisableDeleteNotify 1
Regards, Michel.
Mich
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March 20th, 2018 16:00
https://blogs.msdn.microsoft.com/clustering/2012/04/06/how-to-add-storage-to-clustered-shared-volumes-in-windows-server-2012/
Shouldn't you be doing just a "Quick Format" of NTFS on the volume first and then add it as a CSV into cluster?
Regards, Michel.
RRR
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March 22nd, 2018 00:00
Yup, that's what I'm doing. But even a quick format is slooooow. And I'm seeing it on LUNs presented by VNX, Unity, Unity AFA, XtremIO. Quick Formatting (in diskpart) is always slow. It is slightly faster on all flash arrays, but it's still slow. On average it takes up to 15 minutes for a 2TB LUN, but like in my question, the 9TB LUN took much longer.
Mich
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March 25th, 2018 16:00
That does not sound right. Recommend opening a service request. Run the test, collect an EMCReports and attach to the service request.
Regards, Michel.
RRR
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March 27th, 2018 08:00
I know disabling VAAI on VMware is (or was?) a best practice to speed things up, but there must be another way, right? I will open an SR to have Dell EMC produce a valid answer, but I'd appreciate it if forum peeps have solutions as well :-)
Mich
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March 27th, 2018 20:00
Normally for simple issues yes... but my guess is that there maybe a connection issue, and an EMCReports with the HBAinfo.txt file collected may indicate an issue down 1 x HBA.
RRR
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March 29th, 2018 04:00
every Hyper-V host has the same "problem" and we have dozens of them in various clusters, spread over various data centers, connected to a variety of storage systems (VNX2, Unity, Unity AFA, VMAX, XtremIO, you name it). It simply cannot be a defective HBA or drivers since we have quite a variety of them.
RRR
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April 6th, 2018 02:00
thank you, that was what I was looking for!
dynamox
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April 6th, 2018 07:00
Did it help the issue RRR ?
RRR
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April 9th, 2018 00:00
Absolutely! It worked like a charm. Disable before formatting and enabling it right after if how it's done! Formatting now takes seconds instead of (sometimes) hours.
RRR
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April 9th, 2018 08:00
I wrote a little blog about this. Go see http://www.50mu.net for more info.