We're planning to build a ZFS-based Solaris NFS fileserver environment
with the backend storage being iSCSI-based, in part because of the
possibilities for failover. In exploring things in our test environment,
I have noticed that 'zpool import' takes a fairly long time; about
35 to 45 seconds per pool. A pool import time this slow obviously
has implications for how fast we can import a bunch of pools during
a failover situation, so I'd like to speed it up somehow (ideally in
non-hacky ways).

(Trying to do all of the 'zpool import's in parallel doesn't seem
to speed the collective set of them up relative to doing them
sequentially.)

 My test environment currently has 132 iSCSI LUNs (and 132 pools, one
per LUN, because I wanted to test with extremes) on an up to date S10U4
machine.  A truss of a 'zpool import' suggests that it spends most of
its time opening various disk devices and reading things from them and
most of the rest of the time doing modctl() calls and ZFS ioctls().

(Also, using 'zpool import -d' with a prepared directory that has only
symlinks to the particular /dev/dsk device entries for a pool's LUN
speeds things up dramatically.)

 So, are there any tricks to speeding up ZFS pool import here (short of
the 'zpool import -d' stuff)? Would Sun Cluster manage this faster, or
does its ZFS pool failover stuff basically reduce to 'zpool import' too?

 Thanks in advance.

        - cks
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

Reply via email to