Thorbjørn Donbæk a Senior Storage Developer at VMware created a real cool presentation about ESX Storage Performance Tips. He has worked in the ESX storage group for VMware since November 2001 and enjoys OS level work and particularly in the storage area. Thorbjørn holds a master degree in computer science from the University of Aarhus in Denmark where he also currently lives. His presentation concludes with:
Create VM-specific RDM LUN’s for heavy sequential workloads. For optimal performance create the LUN in it’s own storage group, otherwise let it share a group with other pure sequential workloads. If the VM has several I/O streams make sure you split out the streams to different LUNs whenever possible E.g. don’t let a database log volume AND the database itself reside on the same physical LUN (or storage group). Many random workloads can be put on the same VMFS as long as ‘performance allows’ Also, mixing sequential and random workloads on the same VMFS but on different ESX servers won’t help anything – it just moves the problem back to the storage.
The presentation can be downloaded from the Denmark VMware user group website.
