hi, I have installed omnios with a 32GiB usb stick as the rpool. I have two of those sticks, so I would like to mirror them. rmformat tells me this about the usb sticks: # rmformat Looking for devices... 1. Logical Node: /dev/rdsk/c14t0d0p0 Physical Node: /pci@0,0/pci103c,1609@12,2/storage@3/disk@0,0 Connected Device: Patriot Memory PMAP Device Type: Removable Bus: USB Size: 30.2 GB Label: <None> Access permissions: Medium is not write protected. 2. Logical Node: /dev/rdsk/c15t0d0p0 Physical Node: /pci@0,0/pci103c,1609@12,2/storage@4/disk@0,0 Connected Device: Patriot Memory PMAP Device Type: Removable Bus: USB Size: 30.2 GB Label: <None> Access permissions: Medium is not write protected. The sticks are exactly the same brand and model, so they should be exactly equal. In order to mirror the rpool I followed the instructions in <a href="http://wiki.openindiana.org/oi/2.1+Post-installation">http://wiki.openindiana.org/oi/2.1+Post-installation</a> This is rpool now: # zpool status rpool pool: rpool state: ONLINE scan: none requested config: NAME STATE READ WRITE CKSUM rpool ONLINE 0 0 0 c14t0d0s0 ONLINE 0 0 0 errors: No known data errors But when I try the procedure in the openindiana wiki I get this: # fdisk -B c15t0d0p0 # prtvtoc /dev/rdsk/c14t0d0s2 | fmthard -s - /dev/rdsk/c15t0d0s2 fmthard: Partition 2 specifies the full disk and is not equal full size of disk. The full disk capacity is 61705665 sectors. fmthard: Partition 2 specified as 61737795 sectors starting at 0 does not fit. The full disk contains 61705665 sectors. fmthard: New volume table of contents now in place. # zpool attach rpool c14t0d0s0 c15t0d0s0 invalid vdev specification use '-f' to override the following errors: /dev/dsk/c15t0d0s0 overlaps with /dev/dsk/c15t0d0s2 So apparently the 2 sticks are not exactly the same. Now I got brave (haha) and used the -f swith and it works: # zpool attach -f rpool c14t0d0s0 c15t0d0s0 Make sure to wait until resilver is done before rebooting. # zpool status pool: rpool state: ONLINE status: One or more devices is currently being resilvered. The pool will continue to function, possibly in a degraded state. action: Wait for the resilver to complete. scan: resilver in progress since Mon May 6 20:33:17 2013 53.2M scanned out of 7.13G at 1.06M/s, 1h53m to go 51.0M resilvered, 0.73% done config: NAME STATE READ WRITE CKSUM rpool ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c14t0d0s0 ONLINE 0 0 0 c15t0d0s0 ONLINE 0 0 0 (resilvering) errors: No known data errors Is this expected behaviour? <div>-- Groeten, natxo</div>