I have a Solaris 10 ZFS based NFS server. The physical disks are more or less at their maximum io rates. Performance is very bad - so we will add spindles. The NFS solely serves as storage for XenServer Hypervisors.
I want to know which VM disks (means .vhd files on the storage) are producing most of the load. How can I query the filesystem or maybe nfsd to get an iostat or top like output with filename and reads / writes. Numbers can be absolute or relative.
I tried iosnoop. It definitely goes in the right direction. Unfortunately it seems to be unable to get the filenames on a ZFS filesystem. I have no experience with dtrace. Maybe there is already a script out there?