I am setting up a Debian-based host with a bunch of KVM-based virtual machines. Images of these VMs reside on a ZFS volume (I use ZFS-FUSE 0.6.9). Performance results seem to be very different from my another system, based on CentOS 6. I am concerned that Debian implementation of ZFS-FUSE ignores settings from /etc/zfs/zfsrc
. How can I monitor actual state of ZFS-FUSE, say, ARC cache usage, vdev caches usage, etc?
ZFS-Fuse normally mounts the kstat filesystem on /zfs-kstat, see this announcement. With it, you should be able to access all kstat values (mounting it can fail though).
You can monitor ARC usage and some interesting stats through the arcstat.pl script.