If you have a guest suffering from performance or even your entirely environment and you don’t know where to look at anymore ….
Your problem might be misalignment volumes/disk.
An unaligned partition results in a track crossing and an additional I/O, incurring a penalty on latency and throughput. The additional I/O (especially if small) can impact system resources significantly on some host types. An aligned partitions ensures that the single I/O is serviced by a single device, eliminating the additional I/O and resulting in overall performance improvement.
Some Tips are:
- Always use Virtual Center to create configure your storage (don’t know why someone would do different, but disk alignment is possible on datastore and VMDK)
- Newer OS as Windows 2008 don’t have this issue
- Check your storage vendor for the correct disk alignment
VMWARE has created a good topic about it…here!!
If you are like me and want a visual clarification click here and check this good blog about it.
example of a disk aligned:
