Why doesn't the "Disk" option in the performance tab show up on VMs that are on an NFS Datastore?

[SamTCLEGNZ]

Hi Guys

Looking for a way to monitor I/O performance of indivdual virtual machines in an ESX3.5/VC2.5. Normally we'd use a combination of guest level monitoring tools (perfmon, iostat etc.) and the ESX logging, however the later is not an option when the VM is on a NFS datastore.

Why is that? Is it to do with the lack of a VMFS filesystem?

Cheers

Sam

[marcelo_soares]

I'm not 100% sure about it, but I really think that the disk performance ir related with the fact that iSCSI/FC access disks using an specific VMHBA, which is able to get the numbers needed to measure performance. NFS is a simple mount operation, and do not involve any measurable HBA device.

Marcelo Soares

VMWare Certified Professional 310/410

Technical Support Engineer

Linux Server Senior Administrator

[AndreTheGiant]

VMFS is block based and NFS is file based.

To have I/O detailed stats of NFS you need to watch on the NFS server.

Andre