Khue
Enthusiast
Enthusiast

Aligning VMFS Partitions

I am having some issues aligning partitions. It was recommended that I perform this activity on all of my templates and then going forward all of my newly created vm's will be aligned. One particular issue I am having involves a Windows XP machine with an LSI Logic adapter. I am aligning the vmfs for 64k sectors (Standard for IBM hardware) and therefore I am setting up Windows to align at 32k. The problem I am observing is that after Windows does the initial file copy and reboots for the first time, the system will not boot unless I do at least a quick format. Now I am not certain, but I believe that a quick format will realign the partition to the standard ntfs sector size of like 512 or 1mb.

Has anyone attempted to align a XP vm in this manner? Is there something I am missing? Can Windows XP not handle 32k sector size formatting on the boot partition?

0 Kudos
4 Replies
Troy_Clavell
Immortal
Immortal

we don't align our XP guests, they are already at 32k. It can be debated as to whether disk alignment on your VM's work or not to increase disk performance, however we align all our W2k3 servers at 64K

from the run command type msinfo32

Also, if you haven't seen this whitepaper, it may be useful

0 Kudos
depping
Leadership
Leadership

I wouldn't go through all the trouble just to align a boot OS partition. the performance gains are minimal for this purpose.

Duncan

VCDX | VMware Communities User Moderator

-


Blogging:

Twitter:

If you find this information useful, please award points for "correct" or "helpful".

0 Kudos
JoJoGabor
Expert
Expert

Formatting doesn't make any difference as its the partition that needs to be aligned. Align it to the first 64k though using the diskpart command

create partition primary align=64

I dont know why the machine is not booting. My process is;

Create VMDK and attach to a VM

Create the partition using the command above and quick format

Detach and attach to a new VM and install XP.

This has always worked for me

0 Kudos
Khue
Enthusiast
Enthusiast

Duncan can you expand on this a bit? I would think that the OS partition would be the primary place where you would see the performance gains unless you were doing a lot of writing to another partition. For the most part the XP environment that I am slapping togther is just for QA and Development purposes so I am kind of with you on that. I already have an aligned template for 2k3 server standard. Let's say we have IIS on 30 servers which natively sets itself up on the operating system partition. Wouldn't then the benefits be noticed?

As for the issue I am experiencing, I can get the partition aligned no problem. I have a bench server that I use to do disk operations on. I load the bootable ISO for XP and hit f6 to load the LSI Logic driver. Once I load the driver the setup sees the hdd and setup begins. Most of the defaults are chosen. I opt to leave the partition the way it is (32k sectors with the diskpart 64k aligned option) and the files copy over to the drive. The setup instructs that the files were successfully copied, then reboots. Upon startup, it displays a disk error and will not boot until I reformat the drive again on the bench server. The strangest behavior is that if I choose to Quick Format the drive prior to copying files, the server will boot successfully after the files copy over. I am not sure what is actually involved in a "Quick Format" but I would believe it resets the partition sectors from 32k to whatever the default is. This leads me to conclude that there is something about 32k sectors in my situation, that WindowsXP SP3 cannot deal with.

0 Kudos