9.1 Snapshot 06-05-2012 No ZIL ing root pool ZFS

[minhgi]

In PC-BSD 9.0 release, I can use ZIL on one of my SSD. But with the 9.1 Snapshot 06-5-2012, the default pool had become root. Root pool does not support having a separate ZIL.

Will the final 9.1 release format as root pool?

[kmoore134]

I'll have to ask around about not being able to have a speratem ZIL when
using a ZFS on root system. A quick google search isn't turning anything
up about that. According to the manpage portion about ZIL, it doesn't
mention this anywhere, and seems to indicate that you can add / remove
log devices at will:

----- snip -----
The ZFS Intent Log (ZIL) satisfies POSIX requirements for synchronous
transactions. For instance, databases often require their
transactions to
be on stable storage devices when returning from a system call.
NFS and
other applications can also use fsync(2) to ensure data stability. By
default, the intent log is allocated from blocks within the main pool.
However, it might be possible to get better performance using separate
intent log devices such as NVRAM or a dedicated disk. For example:

# zpool create pool da0 da1 log da2

Multiple log devices can also be specified, and they can be
mirrored. See
the EXAMPLES section for an example of mirroring multiple log devices.

Log devices can be added, replaced, attached, detached, imported and
exported as part of the larger pool. Mirrored log devices can be
removed
by specifying the top-level mirror for the log.

---- snip ----

[cx-u1]

I did try to install in advanced mode from the 'disc selection screen' of the PC-BSD install routine. (See handbook 3.4.2 Advanced Mode )

All went fine and I am very pleased with my new fresh PC-BSD install.

Since I actually did install a ZFS 'root on zfs', without knowing it, I did try to ad a dedicated ZIL (ZFS Intent Log) harddisc - but it failed

After trial and constant error I searched for information and got this statement from the Oracle Documentation Website :

The root pool cannot have a separate log device.

Stated also here:
Solaris ZFS Administration Guide
Oracle Solaris ZFS Administration Guide
Creating and Destroying ZFS Storage Pools

So, best practice would be to install ZFS for PC-BSD 9.1 with the help of it's awsome Installer (which truely did got lots of good work and engagement) with only one harddisc out of a set of two or more harddiscs, to get the mirror funktionality later (man_gparted man_zpool(1M) man_zfs(1M)) after the base-install of PC-BSD?

Any suggestions or any help ?

Regards Chris C.