On Tue, May 16, 2017 at 6:56 AM, Sylvain Leroux <sylv...@chicoree.fr> wrote: > Hi, > I'm investigating BTRFS using an external USB HDD on a Linux Debian > Stretch/Sid system. > > The drive is not reliable. And I noticed when there is an error and the > USB device appears to be dead to the kernel, I am later unable to > remount rw the drive. I can mount it read only though. > > This seems to be a systematic behavior. And it occasionally happens when > the computer wake up from sleep and the drive is still attached. > > Power cycling the disk do not change anything, but restarting the > computer "solves" the issue. > > > I believe this may be caused by BTRFS having issues since the kernel > assign a different device name to the drive when it bring it back > inline? Or BTRFS didn't realize the "original" drive has gone away? > > > Attached are the dmesg output corresponding to my issue. > Initially, the drive was mounted rw and associated to the /dev/sdb > device, the btrfs partition being /dev/sdb1 > After the failure, I power cycled the drive, and the kernel brought it > back as /dev/sdc > > I can mount /dev/sdc1 read only. > But I'm unable to mount it read-write. Interestingly, the message in > dmesg still mention /dev/sdb1 as the device whereas it should be /dev/sdc1. > > > > sylvain@bulbizarre:~$ uname -a > Linux bulbizarre 4.9.0-2-amd64 #1 SMP Debian 4.9.18-1 (2017-03-30) > x86_64 GNU/Linux > sylvain@bulbizarre:~$ btrfs --version > btrfs-progs v4.7.3 > sylvain@bulbizarre:~$ sudo btrfs fi show > Label: 'G-Drive' uuid: 9465dad3-6604-4437-883e-f66386d69ac8 > Total devices 1 FS bytes used 503.34GiB > devid 1 size 931.51GiB used 507.02GiB path /dev/sdc1 > > > > Any clue to help me mounting back the disk without having to restart the > system would be greatly appreciated! > Regards, > - Sylvain.
Seems normal to me. The device is seriously misbehaving. Btrfs gets confused. And it goes read-only to avoid causing more problems by adding writes based on confusing to the misbehaving and unreliable drive. -- Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
