Alignment is something that should be done for EVERY single LUN used by Windows 2003 and below.  Even if you don't think it's needed (i.e. low performance requirements), it should be done anyway.  You never know when a non critical system becomes critical, so it's ALWAYS better to do it right from the beginning than to have to go back and fix it.  If you have some non-aligned volumes out there and they perform fine, then don't worry about it - just fix it when it's time for a hardware refresh.  If you have some stuff that doesn't perform properly, then maybe consider moving the data to an aligned volume.  Alignment does affect all RAID levels - It affects parity volumes more than non parity though.  It's still better to do it for all volumes though.  You never know when you'll need to migrate that RAID10 LUN to RAID5.
Hi All,  Some document mentioned about disk alignment to avoid disk crossing. I have some confusing for following question:  1. Is disk alignment only effective for RAID 5 or parity RAID type (RAID 6)?     RAID 1 and RAID 1/0 will not improve performance.  2. how about offset configuration in CX?      It will only one offset at begining of stripe  or will add many offset to many stripes?  Thanks for clarification. Dennis Dai
disk alignment question