On Mon, Apr 15, 2019 at 12:55:44PM -0700, George Mitchell wrote: > After adding a new drive to a btrfs raid1 array I cannot remount > it. One thing that went wrong for me after having successfully done > this many times before over the last five years is that in this case > I failed to format the partition as btrfs and just left it > unformatted assuming the btrfs command would format it or give me a > warning. But I am not sure that is what caused the problem.
It wouldn't have. That's the correct approach -- btrfs will write the appropriate superblocks and metadata to the new device, effectively destroying anything that was on there before. > So far I have tried physically disconnecting the added drive and > trying to mount read only but that has been unsuccessful. > > I could forge ahead attempting to recover but I prefer to gather any > advice or suggestions I can get before making some foolish mistake. > I appreciate any comments you might have. > > Here is what I am seeing: > > [root@localhost ghmitch]# btrfs check /dev/sda4 > Checking filesystem on /dev/sda4 > UUID: 4b0983d7-8d85-463d-85c1-c20aa3b4fa3b > checking extents > WARNING: unaligned total_bytes detected for devid 4, have > 414224777728 should be aligned to 4096 > WARNING: this is OK for older kernel, but may cause kernel warning > for newer kernels > WARNING: this can be fixed by 'btrfs rescue fix-device-size' You only need to run btrfs check on one of the devices. The device only serves to identify the filesystem, and btrfs check will scan all devices to find the ones that match the device you gave it. btrfs check on the other devices is redundant -- you're checking the *filesystem*, not a *device*. Have you tried using the command recommended in the btrfs check output? (But give us the dmesg first, just in case). > [root@localhost ghmitch]# mount LABEL=common /common > mount: can't find LABEL=common > [root@localhost ghmitch]# mount LABEL=COMMON /common > mount: wrong fs type, bad option, bad superblock on /dev/sdb4, > missing codepage or helper program, or other error > > In some cases useful info is found in syslog - try > dmesg | tail or so. > [root@localhost ghmitch]# mount LABEL=COMMON /common > mount: wrong fs type, bad option, bad superblock on /dev/sdb4, > missing codepage or helper program, or other error > > In some cases useful info is found in syslog - try > dmesg | tail or so. > [root@localhost ghmitch]# > > > I am attaching the output from journalctl for this. I don't see a kernel log attached, just the btrfs check output again. Hugo. -- Hugo Mills | Great oxymorons of the world, no. 4: hugo@... carfax.org.uk | Future Perfect http://carfax.org.uk/ | PGP: E2AB1DE4 |
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