On Thu, Oct 26, 2006 at 02:38:32PM -0700, Chris Gerhard wrote: > To have user quota with ZFS you have to have a file system per user. > However this leads to a very large number of file systems on a large > server. I understand there is work already in hand to make sharing a > large number of file systems faster, however even mounting a large > number of file systems takes a very considerable amount of time. > > Is this being worked on? > > The example I was given was for a system with 30,000 users. So I tried > this on a Thumper runnig Solaris 10 6/06 first with out the file > systems being shared: > > [EMAIL PROTECTED] # time zpool import zpool1 > > real 37m32.98s > user 0m2.42s > sys 1m50.40s > [EMAIL PROTECTED] # > > I need to investigate where all the time is being lost.
Most of this time is spent traversing the datasets (notice the low user/sys time, which indicates we're waiting on I/O). There is no prefetching in the DSL, so this can be slow. See: 6386929 initial "zfs list" is slow > If you share the file systems the time increases even further but as I > understand it that issue is being worked: > > [EMAIL PROTECTED] # time zpool import zpool1 > > real 7h6m28.62s > user 14m55.28s > sys 5h58m13.24s > [EMAIL PROTECTED] # Yes, this is a limitation of the antiquated NFS share subsystem. This is being worked on as part of the sharemgr work. - Eric -- Eric Schrock, Solaris Kernel Development http://blogs.sun.com/eschrock _______________________________________________ zfs-discuss mailing list [email protected] http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
