Legacy HDS Forums

sector alignment

Discussion created by Legacy HDS Forums on Jul 26, 2007
Latest reply on Mar 10, 2008 by Legacy HDS Forums

Originally posted by: mackem



Hi,

Ive been asked whether or not LUSE'ing two OPEN-V-CVS volumes on a USP will affect sector alignment.

To be honest its not really something Ive ever looked into before on HDS storage. 

Apparently the customer has an Exchange server where they have apparently sector aligned the partitions so that they will never issue a write that spans two tracks.  I say "apparently". 

Firstly, is sector alignment applicable on a USP with OPEN-V volumes.

My understanding was that (and this was on the 9980V) that OPEN-V volumes had 128 sectors per track.  When Ive quickly searched google for sector alignment and Exchange it states that it only applies to disks presented as 64 sectors per track.  May be it still works with 128 sectors per track as 128 is a multiple of 64???

Anyway, my questions are as follows -

Does sector alignment apply to USP with OPEN-V CVS volumes?
Does creating a LUSE of multiple OPEN-V CVS volumes affect sector alignment?

BTW, I worked for a company who did some testing on an EVA 5000 and sector alignment and we found that it made no difference whatsoever on performance.

Cheers,

Nigel

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