just to confirm: I run the following dd command to fix the superblocks: dd if=super_dump.sdb of=/dev/sdb bs=1 count=4096 skip=64k dd if=super_dump.sdc1 of=/dev/sdc1 bs=1 count=4096 skip=64k
Thanks, Ben On 8 April 2018 at 12:27, Qu Wenruo <quwenruo.bt...@gmx.com> wrote: > Here you go, all patched super block attached. > > Thanks, > Qu > > On 2018年04月08日 10:14, Ben Parsons wrote: >> Super block of sdb as requested >> >> Thanks, >> Ben >> >> On 8 April 2018 at 11:53, Qu Wenruo <quwenruo.bt...@gmx.com> wrote: >>> >>> >>> On 2018年04月08日 08:57, Ben Parsons wrote: >>>> See attached for requested output. >>>> >>>> Do I still need to recover the super block of sdb? >>> >>> Yep. Please also attach the binary dump of superblock of sdb. >>> >>>> >>>> Could you please point me the right direction for doing the inplace >>>> recovery? >>> >>> I'll provide the patched superblock for both disks (sdb and sdc1) >>> >>> And with them written back to disk, just run "btrfs check" first, if >>> nothing wrong, mount it RW and run scrub. >>> >>> Pretty straightforward. >>> >>> Thanks, >>> Qu >>>> >>>> I have not rebooterd or tried to recover / mount the disc btw. >>>> >>>> Thanks, >>>> Ben >>>> >>>> On 8 April 2018 at 10:02, Qu Wenruo <quwenruo.bt...@gmx.com> wrote: >>>>> >>>>> >>>>> On 2018年04月08日 07:29, Ben Parsons wrote: >>>>>> On 7 April 2018 at 22:09, Qu Wenruo <quwenruo.bt...@gmx.com> wrote: >>>>>>> >>>>>>> >>>>>>> On 2018年04月07日 10:31, Ben Parsons wrote: >>>>>>> [snip] >>>>>>>>> Pretty common hard power reset. >>>>>>>>> >>>>>>>>>> looking at journalctl, there is a large stacktrace from kernel: >>>>>>>>>> amdgpu >>>>>>>>>> (see attached). >>>>>>>>>> then when I booted back up the pool (2 disks, 1TB + 2TB) wouldn't >>>>>>>>>> mount. >>>>>>>>> >>>>>>>>> I'd say such corruption is pretty serious. >>>>>>>>> >>>>>>>>> And what's the profile of the btrfs? If metadata is raid1, we could at >>>>>>>>> least try to recovery the superblock from the remaining disk. >>>>>>>> >>>>>>>> I am not sure what the metadata was but the two disks had no parity >>>>>>>> and just appeared as a single disk with total space of the two disks >>>>>>> >>>>>>> Strangely, for the 2nd disk, it's sdc1, which means it has partition >>>>>>> table. >>>>>>> While for the 1st disk, it's sda, without partition table at all. >>>>>>> Is there any possibility that you just took run partition? >>>>>>> (Or did some program uses it incorrectly?) >>>>>>> >>>>>> >>>>>> I dont quite understand what you are asking. >>>>>> I was always under the impression I could run mount on either >>>>>> partition and it would mount the pool >>>>>> >>>>>>>> >>>>>>>> how would i got about recovering the 2nd disk? attached is >>>>>>> >>>>>>> The 2nd disk looks good, however it's csum_type is wrong. >>>>>>> 41700 looks like garbage. >>>>>>> >>>>>>> Despite that, incompact_flags also has garbage. >>>>>>> >>>>>>> The good news is, the system (and metadata) profile is RAID1, so it's >>>>>>> highly possible for us to salvage (to be more accurate, rebuild) the >>>>>>> superblock for the 1st device. >>>>>>> >>>>>>> Please dump the superblock of the 2nd device (sdc1) by the following >>>>>>> command: >>>>>>> >>>>>>> # dd if=/dev/sdc1 of=super_dump.sdc1 bs=1 count=4096 skip=64k >>>>>>> >>>>>> >>>>>> See attached. >>>>>> >>>>>>> >>>>>>> Unfortunately, btrfs-sb-mod tool added recently doesn't have all needed >>>>>>> fields, so I'm afraid I need to manually modify it. >>>>>>> >>>>>>> And just in case, please paste the following output to help us verify if >>>>>>> it's really sda without offset: >>>>>>> >>>>>>> # lsblk /dev/sda >>>>>>> # grep -obUaP "\x5F\x42\x48\x52\x66\x53\x5F\x4D" >>>>>>> >>>>>> >>>>>> dd if=/dev/sdb of=toGrep.sdb bs=1 count=128M status=progress >>>>>> cat toGrep.sdb | grep -obUaP "\x5F\x42\x48\x52\x66\x53\x5F\x4D" >>>>>> >>>>>> 65600:_BHRfS_M >>>>>> 67108928:_BHRfS_M >>>>> >>>>> Well, the magic number is completely correct, and at correct location. >>>>> >>>>> Would you please run "btrfs inspect dump-super -fFa /dev/sdb" again? >>>>> This time it should provide good data. >>>>> >>>>>> >>>>>>> >>>>>>> Above grep could be very slow since it will try to iterate the whole >>>>>>> disk. It's recommended to dump the first 128M of the disk and then grep >>>>>>> on that 128M image. >>>>>>> >>>>>>> >>>>>>> BTW, with superblock of sdc1 patched, you should be able to mount the fs >>>>>>> with -o ro,degraded, and salvage some data. >>>>>>> >>>>>>> Thanks, >>>>>>> Qu >>>>>> >>>>>> Thank you so much! >>>>>> >>>>>> I am better off copying the data to another disk and then rebuilding the >>>>>> pool? >>>>>> or can I just run a scrub after the super block is fixed? >>>>> >>>>> According to your latest grep output, strangely the 1st device is not >>>>> that corrupted as before. >>>>> >>>>> So I think in-place recover should save you a lot of time. >>>>> >>>>> Thanks, >>>>> Qu >>>>> >>>>>> >>>>>> For reference here is lsblk: >>>>>> >>>>>> sda 8:0 0 465.8G 0 disk >>>>>> ├─sda1 8:1 0 512M 0 part /boot >>>>>> ├─sda2 8:2 0 455.3G 0 part / >>>>>> └─sda3 8:3 0 10G 0 part [SWAP] >>>>>> >>>>>> sdb 8:16 0 931.5G 0 disk >>>>>> -- first disk >>>>>> >>>>>> sdc 8:32 0 1.8T 0 disk >>>>>> └─sdc1 8:33 0 1.8T 0 part >>>>>> -- 2nd disk >>>>>> -- 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
