Re: Unable to rescue RAID5
> You should probably look at `btrfs restore`. I'm not sure how well it works > with the raid56 code, and > you'll need somewhere to put the data being restored, but that's probably > your best option. I tried it already. and then it was "cannot read chunk root". Please take see 1st article of this thread. http://www.spinics.net/lists/linux-btrfs/msg59683.html And I specified -i option for ignore errors, but same result. 1st super mirror(67108864) and 2nd super mirror(274877906944) said all devices are missing like below. But there are all devices... > warning, device 10 is missing > warning, device 8 is missing > warning, device 7 is missing > warning, device 6 is missing > warning, device 5 is missing > warning, device 4 is missing > warning, device 3 is missing > warning, device 2 is missing > warning, device 1 is missing > warning, device 2 is missing > warning, device 3 is missing > warning, device 4 is missing > warning, device 5 is missing > warning, device 6 is missing > warning, device 7 is missing > warning, device 8 is missing > warning, device 10 is missing > warning, device 1 is missing How can I avoid those missing error? Can I restore files if I could avoid those missing errors? Do I need change source code or Is there btrfs command or the option? Thank you Hiroshi Honda -- 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
Re: Unable to rescue RAID5
On 2016-10-14 06:11, Hiroshi Honda wrote: That's the proper answer. In practice... all hope isn't yet lost. I understood the proper answer. I'll take care it in the future. Is there something step/method can I do from this situation? You should probably look at `btrfs restore`. I'm not sure how well it works with the raid56 code, and you'll need somewhere to put the data being restored, but that's probably your best option. -- 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
Re: Unable to rescue RAID5
> That's the proper answer. In practice... all hope isn't yet lost. I understood the proper answer. I'll take care it in the future. Is there something step/method can I do from this situation? Thank you Hiroshi Honda -- 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
Re: Unable to rescue RAID5
Hiroshi Honda posted on Thu, 13 Oct 2016 10:28:19 +0900 as excerpted: > I am using Btrfs RAID5 with 10x4T disks. > Around 2 weeks ago, one disk of it was taking long time when read and > write. > So, I tried replace the disk with new disk by replace command ( btrfs > replace ... ). > But, it failed. So, I added new disk into the array by add command and > then deleted the bad disk by delete command. > But, this deletion failed with error message as well. So, I deleted new > disk from the array at the moment to return to first situation. > But, system is showing some error message with number and the number is > counting up. > So, I rebooted the OS. Because, I felt this situation is something bad. > After that, I can not mount the array... Btrfs parity-raid currently has serious known issues that aren't likely to be corrected in the short term, as to some extent they're in the design. The recommendation is thus not to use btrfs raid56 in production, and if you're already on it, to get off it ASAP, because while it runs fine in normal operation, failure and repair modes simply can't be guaranteed to work as one might expect at this point. There's more about that on the list if you're interested, and others following raid56 mode more closely than I will likely reply with further specific details, as well, but that's the basic raid56 mode status and recommendation in practical terms. As for rescuing files from the array, the proper answer is that btrfs as a whole is still stabilizing, not fully stable and mature, so the sysadmin's rule that if you don't have at least one backup, you are by definition of your failure to backup, defining the data as worth, at maximum, less than the time, hassle and resources necessary to take that backup, applies even more strongly to the not yet fully stable and mature btrfs, than it does to properly stable and mature filesystems. And of course btrfs raid56 mode as a feature is newer and less stabilized than btrfs in general, so the rule that if you don't have a backup, you really are defining the data as of throw-away value, applies even more to anything on btrfs raid56. So to rescue the data, restore it from backups to a preferably non-btrfs- raid56 mode filesystem. Or if you don't have backups, don't worry about it, because you effectively already defined the data as no more than throw-away value by not having those backups in the first place. That's the proper answer. In practice... all hope isn't yet lost. There's some chance to rescue your data, but it'll take time and patience, and likely a significant level of technical understanding along with some help from btrfs experts that know more about the btrfs raid56 technical details than I do. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman -- 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
Unable to rescue RAID5
I am using Btrfs RAID5 with 10x4T disks. Around 2 weeks ago, one disk of it was taking long time when read and write. So, I tried replace the disk with new disk by replace command ( btrfs replace ... ). But, it failed. So, I added new disk into the array by add command and then deleted the bad disk by delete command. But, this deletion failed with error message as well. So, I deleted new disk from the array at the moment to return to first situation. But, system is showing some error message with number and the number is counting up. So, I rebooted the OS. Because, I felt this situation is something bad. After that, I can not mount the array... I copied those disk image by dd and then removed real disks from the system and mounted those image files by losetup. I would appreciate it if you could help this. # uname -a Linux L176 4.7.4-1-ARCH #1 SMP PREEMPT Thu Sep 15 15:24:29 CEST 2016 x86_64 GNU/Linux # ./btrfs version btrfs-progs v4.8.1 # ./btrfs fi show Label: 'space1' uuid: b27e1505-4203-464b-a9d5-96881ca550e0 Total devices 10 FS bytes used 14.47TiB devid1 size 3.64TiB used 1.61TiB path /dev/loop8 devid2 size 3.64TiB used 1.61TiB path /dev/loop6 devid3 size 3.64TiB used 1.61TiB path /dev/loop4 devid4 size 3.64TiB used 1.61TiB path /dev/loop7 devid5 size 3.64TiB used 1.61TiB path /dev/loop9 devid6 size 3.64TiB used 1.61TiB path /dev/loop0 devid7 size 3.64TiB used 1.61TiB path /dev/loop5 devid8 size 3.64TiB used 1.61TiB path /dev/loop2 devid9 size 3.64TiB used 1.61TiB path /dev/loop3 devid 10 size 3.64TiB used 1.61TiB path /dev/loop1 # mount -t btrfs -o ro,degraded,recovery /dev/loop3 /root/oo/ mount: wrong fs type, bad option, bad superblock on /dev/loop3, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so. "-o ro,degraded", "-o ro,recovery" and "-o ro" are same result.. # ./btrfs restore /dev/loop3 /root/oo/ checksum verify failed on 16091506147328 found 1E4E4207 wanted checksum verify failed on 16091506147328 found 1E4E4207 wanted checksum verify failed on 16091506147328 found 58D16B1B wanted 64109AAB checksum verify failed on 16091506147328 found 58D16B1B wanted 64109AAB bytenr mismatch, want=16091506147328, have=3144945314663302585 ERROR: cannot read chunk root Could not open root, trying backup super warning, device 10 is missing warning, device 8 is missing warning, device 7 is missing warning, device 6 is missing warning, device 5 is missing warning, device 4 is missing warning, device 3 is missing warning, device 2 is missing warning, device 1 is missing warning, device 2 is missing warning, device 3 is missing warning, device 4 is missing warning, device 5 is missing warning, device 6 is missing warning, device 7 is missing warning, device 8 is missing warning, device 10 is missing warning, device 1 is missing checksum verify failed on 16091506147328 found 1E4E4207 wanted checksum verify failed on 16091506147328 found 1E4E4207 wanted checksum verify failed on 16091506147328 found 1E4E4207 wanted bytenr mismatch, want=16091506147328, have=0 ERROR: cannot read chunk root Could not open root, trying backup super warning, device 10 is missing warning, device 8 is missing warning, device 7 is missing warning, device 6 is missing warning, device 5 is missing warning, device 4 is missing warning, device 3 is missing warning, device 2 is missing warning, device 1 is missing warning, device 2 is missing warning, device 3 is missing warning, device 4 is missing warning, device 5 is missing warning, device 6 is missing warning, device 7 is missing warning, device 8 is missing warning, device 10 is missing warning, device 1 is missing checksum verify failed on 16091506147328 found 1E4E4207 wanted checksum verify failed on 16091506147328 found 1E4E4207 wanted checksum verify failed on 16091506147328 found 1E4E4207 wanted bytenr mismatch, want=16091506147328, have=0 ERROR: cannot read chunk root Could not open root, trying backup super # ./btrfs-image /dev/loop3 diskid9.img checksum verify failed on 16091506147328 found 1E4E4207 wanted checksum verify failed on 16091506147328 found 1E4E4207 wanted checksum verify failed on 16091506147328 found 58D16B1B wanted 64109AAB checksum verify failed on 16091506147328 found 58D16B1B wanted 64109AAB bytenr mismatch, want=16091506147328, have=3144945314663302585 ERROR: cannot read chunk root ERROR: open ctree failed ERROR: create failed: Success # ./btrfs check --readonly /dev/loop3 checksum verify failed on 16091506147328 found 1E4E4207 wanted checksum verify failed on 16091506147328 found 1E4E4207 wanted checksum verify failed on 16091506147328 found 58D16B1B wanted 64109AAB checksum verify failed on 16091506147328 found 58D16B1B
