On Tue, 21 Oct 2014 13:16:52 +0000 Ronny Egner <ronnyeg...@ronnyegner-consulting.de> wrote:
> Hi Neil, > > > i did a short test and it works so far. Here are my results. Let me know > if you need something more: > > (TL;DR: Wonderful patch. Tested with PAR6 (= six parities) and was able to > recover from losing five disks at once.) Thanks for doing this - it does sound like they are useful. As you note, the patches only include support for btrfs, not for md/raid. I can carry the lib/raid stuff as I am nominally responsible for that, but I cannot send it upstream until there is a user ready to use it. If the btrfs team can be convinced to include the functionality: good. If not, there is nothing I can do to help. There would be a non-trivial amount of effort to integrate this support into md/raid. I am not free to do that at present but if someone else wants to put in the time and effort, I can certainly provide guidance and review. (and please don't send emails about md/raid to me personally. Always include the list at least in 'cc'). Thanks, NeilBrown > > > > The patches apply against 3.14.22 and btrfs-progs 3.12 but not against the > recent 3.18-rc1 and btrfs-progs > 3.12. > > > root@ubuntu-1204-build:~# btrfs --version > Btrfs v3.12-dirty > > root@ubuntu-1204-build:~# uname -a > Linux ubuntu-1204-build 3.14.22 #3 SMP Tue Oct 21 13:00:08 CEST 2014 > x86_64 x86_64 x86_64 GNU/Linux > > > For the tests i used a VM with 4 GB memory, two cores and 15 disks with > 150 GB each. Every disk looked like this: > > root@ubuntu-1204-build:~# fdisk /dev/sdi > > Command (m for help): p > > Disk /dev/sdi: 157.3 GB, 157286400000 bytes > 81 heads, 30 sectors/track, 126419 cylinders, total 307200000 sectors > Units = sectors of 1 * 512 = 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disk identifier: 0x5b5d7269 > > Device Boot Start End Blocks Id System > /dev/sdi1 2048 307199999 153598976 83 Linux > > > File system created: > > root@ubuntu-1204-build:~# mkfs.btrfs -dpar6 -L testpar6 /dev/sdh1 > /dev/sdi1 /dev/sdj1 /dev/sdk1 \ > /dev/sdl1 /dev/sdm1 /dev/sdn1 /dev/sdo1 > /dev/sdp1 > /dev/sdq1 /dev/sdr1 \ > /dev/sds1 /dev/sdt1 /dev/sdu1 /dev/sdv1 > > > Turning ON incompat feature 'extref': increased hardlink limit per file > to 65536 > Turning ON incompat feature 'par3456': raid support with up to six > parities > adding device /dev/sdi1 id 2 > adding device /dev/sdj1 id 3 > adding device /dev/sdk1 id 4 > adding device /dev/sdl1 id 5 > adding device /dev/sdm1 id 6 > adding device /dev/sdn1 id 7 > adding device /dev/sdo1 id 8 > adding device /dev/sdp1 id 9 > adding device /dev/sdq1 id 10 > adding device /dev/sdr1 id 11 > adding device /dev/sds1 id 12 > adding device /dev/sdt1 id 13 > adding device /dev/sdu1 id 14 > adding device /dev/sdv1 id 15 > fs created label testpar6 on /dev/sdh1 > nodesize 16384 leafsize 16384 sectorsize 4096 size 2.15TiB > Btrfs v3.12-dirty > > > Mount: > > > root@ubuntu-1204-build:~# mount /dev/sdh1 /mnt > > Stats: > > root@ubuntu-1204-build:~# df -h > Filesystem Size Used Avail Use% Mounted on > /dev/mapper/vgroot-lvroot 26G 17G 8.4G 67% / > none 4.0K 0 4.0K 0% /sys/fs/cgroup > udev 1.6G 4.0K 1.6G 1% /dev > tmpfs 331M 1.1M 330M 1% /run > none 5.0M 0 5.0M 0% /run/lock > none 1.7G 0 1.7G 0% /run/shm > none 100M 0 100M 0% /run/user > /dev/sdh1 2.2T 2.8M 2.2T 1% /mnt > > > Data, single: total=8.00MiB, used=0.00 > Data, PAR6: total=9.00GiB, used=995.16MiB > System, RAID1: total=8.00MiB, used=16.00KiB > System, single: total=4.00MiB, used=0.00 > Metadata, RAID1: total=1.00GiB, used=65.59MiB > Metadata, single: total=8.00MiB, used=0.00 > > root@ubuntu-1204-build:/mnt# btrfs fi show > Label: testpar6 uuid: 79d3c5e4-74ce-4464-a509-ef666dcd9073 > Total devices 15 FS bytes used 1.04GiB > devid 1 size 146.48GiB used 1.02GiB path /dev/sdh1 > devid 2 size 146.48GiB used 1.00GiB path /dev/sdi1 > devid 3 size 146.48GiB used 1.00GiB path /dev/sdj1 > devid 4 size 146.48GiB used 1.00GiB path /dev/sdk1 > devid 5 size 146.48GiB used 1.00GiB path /dev/sdl1 > devid 6 size 146.48GiB used 1.00GiB path /dev/sdm1 > devid 7 size 146.48GiB used 1.00GiB path /dev/sdn1 > devid 8 size 146.48GiB used 1.00GiB path /dev/sdo1 > devid 9 size 146.48GiB used 1.00GiB path /dev/sdp1 > devid 10 size 146.48GiB used 1.00GiB path /dev/sdq1 > devid 11 size 146.48GiB used 1.00GiB path /dev/sdr1 > devid 12 size 146.48GiB used 2.00GiB path /dev/sds1 > devid 13 size 146.48GiB used 2.00GiB path /dev/sdt1 > devid 14 size 146.48GiB used 1.01GiB path /dev/sdu1 > devid 15 size 146.48GiB used 1.01GiB path /dev/sdv1 > > > Metadata and data still ‚single‘? Bug? Nevermind - lets convert it: > > root@ubuntu-1204-build:/mnt# btrfs balance start -mconvert=raid1 /mnt > Done, had to relocate 4 out of 6 chunks > > root@ubuntu-1204-build:/mnt# btrfs fi df /mnt > Data, single: total=8.00MiB, used=0.00 > Data, PAR6: total=9.00GiB, used=1.02GiB > System, RAID1: total=32.00MiB, used=16.00KiB > Metadata, RAID1: total=1.00GiB, used=67.83MiB > > root@ubuntu-1204-build:/mnt# btrfs balance start -dconvert=par6 /mnt > Done, had to relocate 2 out of 4 chunks > > root@ubuntu-1204-build:/mnt# btrfs fi df /mnt > Data, PAR6: total=9.00GiB, used=1.02GiB > System, RAID1: total=32.00MiB, used=16.00KiB > Metadata, RAID1: total=1.00GiB, used=68.72MiB > > > > OK now lets see what happens if we remove on device. Save a MD5SUM before: > > > root@ubuntu-1204-build:/mnt# md5sum linux-3.14.22.tar > 80af37cdfb2fa2239f79597c914a8c73 linux-3.14.22.tar > > > (Removed one disk and replace it with a brand new, empty one) > > > > > root@ubuntu-1204-build:~# mount /dev/sdh1 /mnt > mount: wrong fs type, bad option, bad superblock on /dev/sdh1, > missing codepage or helper program, or other error > In some cases useful info is found in syslog - try > dmesg | tail or so > > root@ubuntu-1204-build:~# mount /dev/sdh1 /mnt -o degraded > root@ubuntu-1204-build:~# > > root@ubuntu-1204-build:~# btrfs fi show > Label: testpar6 uuid: 79d3c5e4-74ce-4464-a509-ef666dcd9073 > Total devices 15 FS bytes used 31.42GiB > devid 1 size 146.48GiB used 4.00GiB path /dev/sdh1 > devid 2 size 146.48GiB used 5.00GiB path /dev/sdi1 > devid 3 size 146.48GiB used 4.00GiB path /dev/sdj1 > devid 4 size 146.48GiB used 4.00GiB path /dev/sdk1 > devid 5 size 146.48GiB used 4.00GiB path /dev/sdl1 > devid 6 size 146.48GiB used 5.00GiB path /dev/sdm1 > devid 7 size 146.48GiB used 4.03GiB path /dev/sdn1 > devid 8 size 146.48GiB used 4.00GiB path /dev/sdo1 > devid 9 size 146.48GiB used 4.00GiB path /dev/sdp1 > devid 10 size 146.48GiB used 4.00GiB path /dev/sdq1 > devid 11 size 146.48GiB used 4.00GiB path /dev/sdr1 > devid 12 size 146.48GiB used 4.03GiB path /dev/sds1 > devid 13 size 146.48GiB used 4.00GiB path /dev/sdt1 > devid 14 size 146.48GiB used 4.00GiB path /dev/sdu1 > devid 15 size 146.48GiB used 4.00GiB path > > > Lets replace the faulty disk: > > root@ubuntu-1204-build:~# btrfs device add /dev/sdv1 /mnt > root@ubuntu-1204-build:~# btrfs device delete missing /mnt > > In /var/log/syslog: > > [ 191.442050] BTRFS warning (device sdk1): devid 15 missing > [ 581.367659] sdv: sdv1 > [ 598.009968] BTRFS: device label testpar6 devid 16 transid 63 > /dev/sdv1 > [ 614.679654] BTRFS info (device sdk1): relocating block group > 40865103872 flags 4097 > [ 657.889822] BTRFS info (device sdk1): found 64 extents > [ 659.190497] BTRFS info (device sdk1): found 64 extents > [ 659.247765] BTRFS info (device sdk1): relocating block group > 31201427456 flags 4097 > [ 861.359599] BTRFS info (device sdk1): found 132 extents > [ 862.875521] BTRFS info (device sdk1): found 132 extents > [ 862.973499] BTRFS info (device sdk1): relocating block group > 11874074624 flags 4097 > > > > After the ‚delete missing‘ > > Label: testpar6 uuid: 79d3c5e4-74ce-4464-a509-ef666dcd9073 > Total devices 15 FS bytes used 31.42GiB > devid 1 size 146.48GiB used 4.00GiB path /dev/sdh1 > . . . > devid 14 size 146.48GiB used 4.00GiB path /dev/sdu1 > devid 16 size 146.48GiB used 4.00GiB path /dev/sdv1 > > > The md5 checksum is still correct: > > root@ubuntu-1204-build:/mnt# md5sum linux-3.14.22.tar > 80af37cdfb2fa2239f79597c914a8c73 linux-3.14.22.tar > > > > > > > > > > Hardcore test: PAR6 = 6 parities. Let´s see what happens if i remove five > disks and replace with with empty ones. > > Before i did that the metadata format was converted to PAR6 as well: > > > root@ubuntu-1204-build:~# btrfs fi df /mnt/ > Data, PAR6: total=36.00GiB, used=31.32GiB > System, PAR6: total=144.00MiB, used=16.00KiB > Metadata, PAR6: total=1.12GiB, used=101.81MiB > > > > > root@ubuntu-1204-build:~# mount /dev/sdn1 /mnt/ -o degraded > > > root@ubuntu-1204-build:~# btrfs fi show > Label: testpar6 uuid: 79d3c5e4-74ce-4464-a509-ef666dcd9073 > Total devices 15 FS bytes used 31.42GiB > devid 1 size 146.48GiB used 4.00GiB path > devid 2 size 146.48GiB used 5.00GiB path > devid 3 size 146.48GiB used 4.00GiB path > devid 4 size 146.48GiB used 4.00GiB path > devid 5 size 146.48GiB used 4.00GiB path > devid 6 size 146.48GiB used 5.00GiB path /dev/sdm1 > devid 7 size 146.48GiB used 4.03GiB path /dev/sdn1 > devid 8 size 146.48GiB used 4.00GiB path /dev/sdo1 > devid 9 size 146.48GiB used 4.00GiB path /dev/sdp1 > devid 10 size 146.48GiB used 4.00GiB path /dev/sdq1 > devid 11 size 146.48GiB used 4.00GiB path /dev/sdr1 > devid 12 size 146.48GiB used 4.03GiB path /dev/sds1 > devid 13 size 146.48GiB used 4.00GiB path /dev/sdt1 > devid 14 size 146.48GiB used 4.00GiB path /dev/sdu1 > devid 16 size 146.48GiB used 4.00GiB path /dev/sdv1 > > > Now let´s bring it back in shape and add five new, empty disks: > > btrfs device add /dev/sdh1 /dev/sdi1 /dev/sdj1 /dev/sdk1 /dev/sdl1 /mnt > btrfs delete missing > <<wait>> > root@ubuntu-1204-build:~# btrfs fi show > Label: testpar6 uuid: 79d3c5e4-74ce-4464-a509-ef666dcd9073 > Total devices 15 FS bytes used 1.09GiB > devid 6 size 146.48GiB used 2.14GiB path /dev/sdm1 > devid 7 size 146.48GiB used 2.14GiB path /dev/sdn1 > devid 8 size 146.48GiB used 2.14GiB path /dev/sdo1 > devid 9 size 146.48GiB used 2.14GiB path /dev/sdp1 > devid 10 size 146.48GiB used 2.14GiB path /dev/sdq1 > devid 11 size 146.48GiB used 2.14GiB path /dev/sdr1 > devid 12 size 146.48GiB used 2.14GiB path /dev/sds1 > devid 13 size 146.48GiB used 2.14GiB path /dev/sdt1 > devid 14 size 146.48GiB used 2.14GiB path /dev/sdu1 > devid 16 size 146.48GiB used 2.14GiB path /dev/sdv1 > devid 17 size 146.48GiB used 2.14GiB path /dev/sdh1 > devid 18 size 146.48GiB used 2.14GiB path /dev/sdi1 > devid 19 size 146.48GiB used 2.14GiB path /dev/sdj1 > devid 20 size 146.48GiB used 2.14GiB path /dev/sdk1 > devid 21 size 146.48GiB used 2.14GiB path /dev/sdl1 > > > > > > And now the checksum: > > root@ubuntu-1204-build:/mnt# md5sum linux-3.14.22.tar > 80af37cdfb2fa2239f79597c914a8c73 linux-3.14.22.tar > > Checksum matches! > > So.. this looks *very* good to me. > > > > > > > > > Mit freundlichen Grüßen > Ronny Egner > -- > Ronny Egner > Oracle Certified Master 11g (OCM) > > Mobile: +49 170 8139903 > EMail: ronnyeg...@ronnyegner-consulting.de > <mailto:roonnyeg...@ronnyegner-consulting.de> > > > > > Am 21.10.14 09:27 schrieb "NeilBrown" unter <ne...@suse.de>: > > >On Tue, 21 Oct 2014 06:33:47 +0000 Ronny Egner > ><ronnyeg...@ronnyegner-consulting.de> wrote: > > > >> Dear All, > >> > >> i was wondering what happened with the patch posted by Andrea Mazzoleni > >> back in Februrary 2014 (this Thread: > >> http://thread.gmane.org/gmane.linux.kernel/1654735). > >> > >> Why wash´t it added to the code? Something missing/wrong? > >> > >> In my opinion the posted patch is awesome and would enable a unique > >> feature that no other UNIX-like operating system currently has. > >> > > > >Could you report your test results please. > > > >NeilBrown >
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