My experience with ZFS! ( Creating ZFS filesystem for /usr )
By vineeth on Dec 03, 2006
Few days back, I was playing with ZFS and got a strange idea to convert my /usr and /opt to ZFS. I created a ZFS pool and then created two filesystems:
sparkle@~# zfs list
NAME USED AVAIL REFER MOUNTPOINT
pool 3.50G 5.31G 24.5K /pool
pool/opt 1.45G 5.31G 1.45G /pool/opt
pool/usr 2.05G 5.31G 2.05G /pool/usr
I copied the contents of /usr and /opt to ZFS filesystems and changes the mount point of these to filesystems to /usr and /opt. And I rebooted to see the system going into maintenance mode . The system did not boot up because ZFS mounting was coming some wher later in the boot process and system could not find the /usr. With the help of my colleagues Moinak and Ananth (and of course Google ), we solved the issue. Here is how you can mount /usr as a ZFS file system.
1)Create the filesystem and copy the contents.
2)Set the mount point as legacy
sparkle@~# zfs set mountpoint=legacy pool/usr
3)Add an entry in the vfstab like:
pool/usr - /usr zfs - yes -
Reboot the system and Enjoy the power of ZFS !