I am currently running an Ubuntu 12.10 Desktop with some zfs pools. I have installed ZFS using the following instructions and from the PPA it contains: https://wiki.ubuntu.com/ZFS
I have a bursty/fluctuating write performance issue which is apparently a known issue. I have found several posts where people have the exact same problem. Constant fluctuating writes. According to the http://wiki.freebsd.org/ZFSTuningGuide I need to apply some settings to "avoid the bursty IO that's often seen with ZFS." This must be done in the /boot/loader.conf.
Since Ubuntu does not use that, as far as I can tell, I have no idea how to apply settings like:
vfs.zfs.prefetch_disable="1" vfs.zfs.txg.timeout="5" kern.maxvnodes=250000 vfs.zfs.write_limit_override=1073741824 vfs.zfs.arc_min="512M" vfs.zfs.arc_max="1536M" vm.kmem_size_max="8G" vm.kmem_size="6G"
Which is mentioned in the general tuning section. Other sources say use sysctl. But when I do I get this: sudo sysctl vfs.zfs.prefetch_disable="1" sysctl: cannot stat /proc/sys/vfs/zfs/prefetch_disable: No such file or directory
I cannot find anything for vfs or zfs in /proc/sys.
Where does one do this kind of thing in Ubuntu?