zfs-geli-zfs: opinions/suggestions

[Jacob Yocom-Piatt]

lo all,

have a freebsd 7.0-beta4 machine attached to an external disk enclosure 
and would like feedback on the following setup: have RAID-Z on 4 disks, 
ZFS volume that takes up entire RAID-Z, use ZVOL from volume for 
encryption via geli, use .eli (decrypted) device to make another ZFS 
pool. the idea being "no time/resources wasted doing fscks plus 
encryption sans hardware RAID".

translated to commands this reads:

# zpool create p_a raidz /dev/mfid1 /dev/mfid2 /dev/mfid3 /dev/mfid4
# zpool list
NAME                    SIZE    USED   AVAIL    CAP  HEALTH     ALTROOT
p_a                    2.72T   4.02G   2.71T     0%  ONLINE     -
# zfs create -V 2048g p_a/vol
# geli init -K /root/p_a.key -s 4096 -l 256 /dev/zvol/p_a/vol
# geli attach -k /root/p_a.key /dev/zvol/p_a/vol
# zpool create a /dev/zvol/p_a/vol.eli

i got a reboot while scp-ing some files to /a (only got ~3 GB in) from 
another machine with the above setup. am currently waiting far too long 
for a rm -R <directory> to complete under /a. will test if any of this 
behavior is repeatable.

i welcome opinions or suggestions on the stability of such a setup 
(ZFS-geli-ZFS) and if this is not stable, as the reboot i just 
experienced would indicate, suggestions on alternative configurations 
that allow use of geli and minimize or eliminate fsck time. i do have a 
preference for no hardware RAID since it ties us to a particular card. 
will furnish a proper bug report if the reboots are repeatable in the 
aforementioned scenario.

NOTE: please CC me since i am not yet subscribed to this list

cheers,
jake

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