I recently discovered a free tool that will assist VMware admins in detecting and resolving VMware VM partition alignment issues. VM partition alignment is critical in reducing i/o at the storage array level for VMware infrastructure. Essentially poorly aligned VM partitions can double or triple the i/o cycles to the storage array. If VM admins ignore this problem or are unaware of the issue, this problem can snowball and consume excessive storage i/o limiting the number of VM’s that can be supported on a VM infrastructure.
The free tool is called UberAlign. UberAlign will scan your VM infrastructure for misaligned VM’s and optionally re-align the VM to the correct offset.
More information about UberAlign can be found here.
More detailed information about VMware VM alignment issues can be found here.