Booting off ZFS pool with failed ZIL/cache device

[Stefan Bethke]

Folks,

my ZIL/cache SSD apparently just died. Rebooting the system with the SATA M.2 SSD hung, so I removed the card from the system.

On powerup, loader acts normally, all four SATA disks (main Raid-Z1 devices) are all probed successfully, but mount root fails:

ZFS filesystem version: 5
ZFS storage pool version: features support (5000)
Timecounters tick every 1.000 msec
ada0 at ahcich0 bus 0 scbus0 target 0 lun 0
ada0: <TOSHIBA MD04ACA50D FS2A> ATA8-ACS SATA 3.x device
ada0: Serial Number Z5Q7K0RIFFRC
ada0: 600.000MB/s transfers (SATA 3.x, UDMA5, PIO 8192bytes)
ada0: Command Queueing enabled
ada0: 4769307MB (9767541168 512 byte sectors)
ada1 at ahcich2 bus 0 scbus2 target 0 lun 0
ada1: <TOSHIBA MD04ACA50D FS2A> ATA8-ACS SATA 3.x device
ada1: Serial Number Y5PIK0A2FFRC
ada1: 300.000MB/s transfers (SATA 2.x, UDMA5, PIO 8192bytes)
ada1: Command Queueing enabled
ada1: 4769307MB (9767541168 512 byte sectors)
ada2 at ahcich3 bus 0 scbus3 target 0 lun 0
ada2: <TOSHIBA MD04ACA50D FS2A> ATA8-ACS SATA 3.x device
ada2: Serial Number 36D2K0VZFFRC
ada2: 300.000MB/s transfers (SATA 2.x, UDMA5, PIO 8192bytes)
ada2: Command Queueing enabled
ada2: 4769307MB (9767541168 512 byte sectors)
ada3 at ahcich4 bus 0 scbus4 target 0 lun 0
ada3: <TOSHIBA MD04ACA50D FS2A> ATA8-ACS SATA 3.x device
ada3: Serial Number Z5SDK0J3FFRC
ada3: 300.000MB/s transfers (SATA 2.x, UDMA5, PIO 8192bytes)
ada3: Command Queueing enabled
ada3: 4769307MB (9767541168 512 byte sectors)
pass4 at ahciem0 bus 0 scbus6 target 0 lun 0
pass4: <AHCI SGPIO Enclosure 1.00 0001> SEMB S-E-S 2.00 device
Trying to mount root from zfs:p2/be/11 []...
GEOM_MIRROR: Device mirror/p2swap launched (4/4).
random: unblocking device.
Mounting from zfs:p2/be/11 failed with error 6; retrying for 3 more seconds
Mounting from zfs:p2/be/11 failed with error 6.

Loader variables:
 vfs.root.mountfrom=zfs:p2/be/11

Manual root filesystem specification:
 <fstype>:<device> [options]
     Mount <device> using filesystem <fstype>
     and with the specified (optional) option list.

   eg. ufs:/dev/da0s1a
       zfs:tank
       cd9660:/dev/cd0 ro
         (which is equivalent to: mount -t cd9660 -o ro /dev/cd0 /)

 ?               List valid disk boot devices
 .               Yield 1 second (for background tasks)
 <empty line>    Abort manual input

mountroot> 

Is there an easy way to boot into single user mode and remove the ZIL/cache devices that are not there anymore? Or do I need a USB key to boot off of and zfs import the pool first?


Thanks,
Stefan

-- 
Stefan Bethke <stb at lassitu.de>   Fon +49 151 14070811