Hi ! I have a faulty drive in my raid10 and want it to be replaced. Working drive are xvd[bef] and replacement drive is xvdc. When I mount my drive in RW: #mount -odegraded /dev/xvdb /tank #dmesg -c [ 6207.294513] btrfs: device fsid 728ef4d8-928c-435c-b707-f71c459e1520 devid 1 transid 551398 /dev/xvdb [ 6207.327357] btrfs: allowing degraded mounts [ 6207.477041] btrfs: bdev (null) errs: wr 15211054, rd 3038899, flush 0, corrupt 0, gen 0 [ 6219.703606] Btrfs: too many missing devices, writeable mount is not allowed [ 6219.785929] btrfs: open_ctree failed When I mount my drive in RO: #mount -odegraded,ro /dev/xvdb /tank #btrfs filesystem show Label: none uuid: 728ef4d8-928c-435c-b707-f71c459e1520 Total devices 4 FS bytes used 4.70TiB devid 1 size 2.73TiB used 2.73TiB path /dev/xvdb devid 2 size 2.73TiB used 2.73TiB path devid 3 size 2.73TiB used 2.73TiB path /dev/xvde devid 4 size 2.73TiB used 2.73TiB path /dev/xvdf Btrfs v3.12 Of course, because my mount is in RO, i can't add device and do a balance: #btrfs device add /dev/xvdc /tank ERROR: error adding the device '/dev/xvdc' - Read-only file system Neither a "replace without disk": #btrfs replace start -Br 2 /dev/xvdc /tank ERROR: ioctl(DEV_REPLACE_START) failed on "/tank": Read-only file system, no error FYI I'm on ubuntu 14.04 with btrfs 3.12 Any idea ? Thanks ! -- fensoft -- 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