On Wed, Dec 09, 2015 at 10:19:41AM +0000, Duncan wrote: > Alistair Grant posted on Wed, 09 Dec 2015 09:38:47 +1100 as excerpted: > > > On Tue, Dec 08, 2015 at 03:25:14PM +0000, Duncan wrote: > > Thanks again Duncan for your assistance. > > > > I plugged the ext4 drive I planned to use for the recovery in to the > > machine and immediately got a couple of errors, which makes me wonder > > whether there isn't a hardware problem with the machine somewhere. > > > > So decided to move to another machine to do the recovery. > > Ouch! That can happen, and if you moved the ext4 drive to a different > machine and it was fine there, then it's not the drive. > > But you didn't say what kind of errors or if you checked SMART, or even > how it was plugged in (USB or SATA-direct or...). So I guess you have > that side of things under control. (If not, there's some here who know > quite a bit about that sort of thing...)
Yep, I'm familiar enough with smartmontools, etc. to (hopefully) figure this out on my own. > > > So I'm now recovering on Arch Linux 4.1.13-1 with btrfs-progs v4.3.1 > > (the latest version from archlinuxarm.org). > > > > Attempting: > > > > sudo btrfs restore -S -m -v /dev/sdb /mnt/btrfs-recover/ ^&1 | tee > > btrfs-recover.log > > > > only recovered 53 of the more than 106,000 files that should be > > available. > > > > The log is available at: > > > > https://www.dropbox.com/s/p8bi6b8b27s9mhv/btrfs-recover.log?dl=0 > > > > I did attempt btrfs-find-root, but couldn't make sense of the output: > > > > https://www.dropbox.com/s/qm3h2f7c6puvd4j/btrfs-find-root.log?dl=0 > > Yeah, btrfs-find-root's output deciphering takes a bit of knowledge. > Between what I had said and the wiki, I was hoping you could make sense > of things without further help, but... > > ... It turns out that a drive from a separate filesystem was dying and causing all the weird behaviour on the original machine. Having two failures at the same time (drive physical failure and btrfs filesystem corruption) was a bit too much for me, so I aborted the btrfs restore attempts, bought a replacement drive and just went back to the backups (for both failures). Unfortunately, I now won't be able to determine whether there was any connection between the failures or not. So while I didn't get to practice my restore skills, the good news is that it is all back up and running without any problems (yet :-)). Thank you very much for the description and detailed set of steps for using btrfs-find-root and restore. While I didn't get to use them this time, I've added links to the mailing list archive in my btrfs wiki user page so I can find my way back (and if others search for restore and find root they may also benefit from your effort). Thanks again, Alistair -- 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