ZFS on root and disk write caching.

[Andrew Hill]

I don't have a definite answer to your first two questions (I've got a
similar set up and would be interested to get some definite answers to
those) however I'd like to comment on your third point...

On May 21, 11:00 pm, arnaud.houdele... at tzim.net (Arnaud Houdelette) wrote:
> 3. I'd like to keep the storage pool (zraid1) separated from the system
> pool (just one disk). The wiki states that we may encounter problems
> with more than one pool in use : is it still the case ?

as for encountering problems with multiple zpools, my impression from the
mailing lists is that it seems to work fine for some people and not for
others... (i'm in the latter category, unfortunately)

but what struck me as odd is the desire to create two separate zpools - one
for data storage and one for the system. i think one of zfs's greatest
strengths is the abstraction/separation between disks and filesystems.
unless you're planning on removing/recreating the raidz1 pool in the near
future, it seems a bit odd to put your system on a single/separate,
non-redundant drive when you could just create a raidz across all four disks
with storage and system filesystems in the one raidz pool. this way you
don't lose anything if the disk you chose to run the OS from happens to
fail, or even just gets a bad sector in an unfortunately crucial location...

And even if you were going to recreate the raidz pool in the near future, it
shouldn't be too hard to backup the system filesystems with zfs
snapshot/send/receive commands, recreate the pool and then restore the
system filesystems from the backup

Andrew