If you are not already aware, VMware shops have been challenged for some time now (several years, in fact) with partition alignment problems in the guest file system… VMware has been aware of this for years, and has offered guidance on how to fix the issue (http://www.vmware.com/pdf/esx3_partition_align.pdf). Although Microsoft has fixed this problem in Windows 7 and Windows Server 2008, partition alignment can still prove problematic on older virtual machines that are running Windows Server 2003, Windows XP, and Linux distributions on EXT3 and earlier. Mis-aligned file system partitions can cause I/o problems on the storage back-end, sometimes creating 3-4x the I/o on the array. There are great posts by Duncan (http://www.yellow-bricks.com/2010/04/08/aligning-your-vms-virtual-harddisks/) and Kevin (http://www.blueshiftblog.com/?p=300) on what the issues are and some of the tools available.
Earlier this year, Nick Weaver (a member of the vSpecialist team) took it on to create a highly versatile and functional alignment tool (there have been a couple others out there, but this one is better – read on). It is free to download off the link at the top of this email, and offers features such as:
- Allows for fast alignment checking of virtual machines with detailed logging.
- Can perform alignment to any offset you want. Even the crazy ones that you shouldn’t choose.
- Works with both Windows 2000/XP/2003/2008 (NTFS) and Linux Distros (EXT2/EXT3/EXT4).
- Is able to work on NTFS boot drives perfectly. It does this by rewriting NTFS Metadata (the right way).
- Auto detects Windows 2008 and Windows 7 native installs (alignment not needed). Will not touch a System Reserved Partition (important for Windows 2008).
- Preserves all Windows drive mapping (AFAIK only one to do so). This means no having to remap drive letters and complete support for non “C:” system drives with some Windows builds (some Citrix stuff).
- Doesn’t trash the NTFS and Boot mirrors like other tools.
- Handles Primary and Extended partitions like it is no big deal on both Windows and Linux.
- Has the ability to handle multiple disks for a VM.
- Multiple disks + Multiple Partitions + Multiple types (primary, logical) + Multiple file systems (NTFS, EXT#) = no problem
- Also allows for optional Space Reclamation on both NTFS and Ext! That’s right: you can choose to do space reclamation at the same time as an alignment or as a option to itself. This means you can retrieve space no longer used on Thin VM’s using UBERAlign.
This is only about 1/3 the list of features….
Be sure to check it out!