Hi, I've just encountered a hard disk crash in one of my btrfs pools. sudo btrfs filesystem show failed to open /dev/sr0: No medium found Label: none uuid: 545e95c6-d347-4a8c-8a49-38b9f9cb9add Total devices 3 FS bytes used 112.70GB devid 1 size 100.61GB used 89.26GB path /dev/sdc6 devid 2 size 93.13GB used 84.00GB path /dev/sdc1 *** Some devices missing The device which is missing is /dev/sdb. I have replaced it with a new hard disk. How do I add it back to the volume and fix the device missing? The pool is expected to mount to /samples (it is not mounted yet). I tried this - which fails: sudo btrfs device add /dev/sdb /samples ERROR: error adding the device '/dev/sdb' - Inappropriate ioctl for device Why isn't this working? I also tried this: sudo mount -o recovery /dev/sdc1 /samples mount: wrong fs type, bad option, bad superblock on /dev/sdc1, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so same with /dev/sdc6 I ran btrfsck --repair on /dev/sdc1 and /dev/sdc6. Apart that it reports a device is missing (/dev/sdb) seems okay. I also tried: sudo btrfs filesystem df /samples ERROR: couldn't get space info on '/samples' - Inappropriate ioctl for device and as I'm supposed to have a snapshot, this (but I suppose it's helpless as the volume isn't mounted) btrfs subvolume snapshot /samples/malwareSnapshot /before ERROR: error accessing '/samples/malwareSnapshot' Please help me out, thanks Axelle. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html