Misaligned LUNs in Windows 2008 servers?

[pravinb]

Hi All,

We have multiple LUN's assigned to windows 2008 server running sql. When I run the command "lun alignment show" on the controller for some of the LUN's I am getting the alignment status as "indeterminate" and "misaligned". These are supposed to be servers that were newly installed with windows 2008 and going through the support site it is clear that it should not be ideally having issues with misalignment.

Multiprotocol type: windows_2008

Has anyone come across this issue before? Requesting your assistance on the same.

Thanks

[jherlihy1 · Accepted solution]

Hi,

I've seen SQL LUNs in the past only doing partial writes (because of the nature of the DB which writes in 512B chunks) which could be misinterpreted as misalignment (or indeterminate). In this case wouldn't need to worry about it.

Windows 2008 LUNs shouldn't have issues with alignment (if you use the correct multiprotocol type as you have) as it uses a 1MB offset. You can check the offset in msinfo32 by going to Components-->Storage-->Disks, then checking the value of "Partition Starting Offset" - as long as it's divisible by 4KB then you should be ok.

Cheers,

John

[pravinb]

Thanks John. I wil inform the SQL team to check the offset value.