NTFS cluster size

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imrevo
Posts: 26
Joined: Tue Jan 12, 2010 9:20 am
Location: Germany

Mon Apr 08, 2013 4:38 am

Good morning,

what NTFS cluster size should be chosen for iSCSI targets? 4K would be default, but I think I've read something about 64K being better for iSCSI targets.

bye
Volker
jeddyatcc
Posts: 49
Joined: Wed Apr 25, 2012 11:52 pm

Mon Apr 08, 2013 12:36 pm

64k is the suggested size, but I would really recommend testing performance. While Starwind writes in 64k blocks, I have gotten better performance using 4k or 32k block sizes on different arrays.
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Anatoly (staff)
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Wed Apr 10, 2013 10:10 am

Totally agree with jeddyatcc - this should be the test based choice.
Best regards,
Anatoly Vilchinsky
Global Engineering and Support Manager
www.starwind.com
av@starwind.com
imrevo
Posts: 26
Joined: Tue Jan 12, 2010 9:20 am
Location: Germany

Wed Apr 10, 2013 10:29 am

Hi Anatoly,
Anatoly (staff) wrote:Totally agree with jeddyatcc - this should be the test based choice.
Will be done as soon as the new drive arrives :-) I'll keep you posted.

Already did some testing with the NTFS cluster size within a VM: No performance difference worth mentioning between 4K and 64K, base disk of the HA-Image was on a disk formatted with 4K NTFS cluster size.

bye
Volker
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Anatoly (staff)
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Mon Apr 15, 2013 8:56 am

Any update here please?
Best regards,
Anatoly Vilchinsky
Global Engineering and Support Manager
www.starwind.com
av@starwind.com
imrevo
Posts: 26
Joined: Tue Jan 12, 2010 9:20 am
Location: Germany

Tue Apr 16, 2013 4:00 am

Good morning Anatoly,
Anatoly (staff) wrote:Any update here please?
I stayed with 4K as the difference between 4K, 32K and 64K has been neglectable during my tests.

bye
Volker
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Anatoly (staff)
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Thu Apr 18, 2013 4:06 pm

Thanks for the heads up!
Best regards,
Anatoly Vilchinsky
Global Engineering and Support Manager
www.starwind.com
av@starwind.com
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