VMware Cloud Community
alex6
Contributor
Contributor
‎03-06-2007 01:21 PM

Disk Alignment and RDM

Hi,

I am using VI3. I have created a LUN, and an RDM (Physical) to access it. I am running Windows 2003 Enterprise. Do I have to align this disk with a 64Byte header.

Note: When creating the LUN, I created it will a 16Byte segment size as I believe this will give me an optimum performance gain as the LUN will be used with 2003 MSCS and I will be storing my SQL 2005 db on this LUN.

Thanks,

Alex

0 Kudos
5 Replies
boydd
Champion
Champion
‎03-06-2007 01:31 PM

What the backend storage (SAN type)?

DB

DB
0 Kudos
whynotq
Commander
Commander
‎03-06-2007 01:31 PM

I would say "yes" disk alignment to the OS is necessary, particuarly with Windows, regardless of the disk type.

0 Kudos
alex6
Contributor
Contributor
‎03-06-2007 01:34 PM

My Backend Sotarge is a SAN, its a IBM DS4100 RAID 10.

0 Kudos
kix1979
Immortal
Immortal
‎03-06-2007 01:35 PM

I agree with whynotg, disk alignment is critical for Windows VMs. It can have a significant impact to overall performance. RDM or VMDK should both be aligned.

Thomas H. Bryant III
0 Kudos
alex6
Contributor
Contributor
‎03-06-2007 01:36 PM

Is a 16KB Segment size a good choice for a LUN holding my MS SQL 2005 database?

Would it be worth changing the NTFS allocation unit size aswell?

Thanks again,

Alex

0 Kudos