From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian von Bidder Subject: slow umount + btrfs-show odditiy Date: Mon, 28 Dec 2009 15:59:46 +0100 Message-ID: <200912281559.52522@fortytwo.ch> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart3737049.XsUg3xOSzW"; protocol="application/pgp-signature"; micalg=pgp-sha1 To: linux-btrfs@vger.kernel.org Return-path: List-ID: --nextPart3737049.XsUg3xOSzW Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Heyho! Running btrfs on a QNAP (ARM Platform), 1.8T Filesystem on most of 4 x 500G= =20 disks, raid 1 for data + metadata. Filled with 300G files (dirvish trees,= =20 so lots of hardlinks. Files are backups of "normal" user + root filesystem= s=20 of a few PCs, so quite a mix in filesizes.) [[[ Eventually I'll want to replace dirvish by plain rsync and use btrfs=20 timestamps to get snapshots. Got to prove stability first. ]]] After copying the files from the prvevious location onto this filesystem,=20 btrfs-show shows only 450G used on one disk and 30G or so on the other thre= e=20 disks (sorry, didn't preserve the output.) In any case, the other three=20 disks didn't have enough to contain all the data duplicated in raid1=20 fashion. "btrfs-vol -b" (obviously took quite some hours), now I have: +++ Label: none uuid: 9a41b0eb-3f9b-4f56-852e-13068829f8aa Total devices 4 FS bytes used 393.45GB devid 3 size 450.49GB used 389.00GB path /dev/sdc2 devid 4 size 450.49GB used 396.01GB path /dev/sdd2 devid 1 size 450.49GB used 396.01GB path /dev/sda2 devid 5 size 450.49GB used 253.00GB path /dev/sdb2 Btrfs v0.19-4-gab8fb4c-dirty +++ Which is strange as well. Given that the real data is ~400G, I'd have=20 expected the disks to be fileed with 4 x 200G plus some metadata, but this= =20 looks like almost twice as much as I'd expect. I'm no fs debugger, so it might be anything of -> btrfs-show is far off -> metadata on btrfs is quite big -> I don't have raid1 (data + metadata mirrored inn two places) but the=20 stuff is being mirrored on more disks than necessary. -> or something completely different... And after that, umount took about 5min (the machine has only 512M, and I=20 waited a few hours after "btrfs-vol -b" has completed before I unmounted,=20 but I did not issue a sync first.) The kernel triggered twice or so with the following: Dec 28 15:45:08 syydelaervli kernel: [97580.340641] INFO: task umount:12765= blocked for more than 120 seconds. Dec 28 15:45:08 syydelaervli kernel: [97580.340674] "echo 0 > /proc/sys/ker= nel/hung_task_timeout_secs" disables this message. Dec 28 15:45:08 syydelaervli kernel: [97580.340699] umount D c02b080= c 0 12765 12681 0x00000000 Dec 28 15:45:08 syydelaervli kernel: [97580.340749] [] (schedule+= 0x424/0x488) from [] (bdi_sched_wait+0xc/0x18) Dec 28 15:45:08 syydelaervli kernel: [97580.340787] [] (bdi_sched= _wait+0xc/0x18) from [] (__wait_on_bit+0x5c/0xa8) Dec 28 15:45:08 syydelaervli kernel: [97580.340821] [] (__wait_on= _bit+0x5c/0xa8) from []=20 (out_of_line_wait_on_bit+0xac/0xc4) Dec 28 15:45:08 syydelaervli kernel: [97580.340857] [] (out_of_li= ne_wait_on_bit+0xac/0xc4) from []=20 (sync_inodes_sb+0x68/0x100) Dec 28 15:45:08 syydelaervli kernel: [97580.340894] [] (sync_inod= es_sb+0x68/0x100) from [] (__sync_filesystem+0x64/0x94) Dec 28 15:45:08 syydelaervli kernel: [97580.340932] [] (__sync_fi= lesystem+0x64/0x94) from []=20 (generic_shutdown_super+0x28/0x110) Dec 28 15:45:08 syydelaervli kernel: [97580.340970] [] (generic_s= hutdown_super+0x28/0x110) from []=20 (kill_anon_super+0x14/0x3c) Dec 28 15:45:08 syydelaervli kernel: [97580.341008] [] (kill_anon= _super+0x14/0x3c) from [] (deactivate_super+0x6c/0x90) Dec 28 15:45:08 syydelaervli kernel: [97580.341044] [] (deactivat= e_super+0x6c/0x90) from [] (sys_umount+0x2bc/0x2e8) Dec 28 15:45:08 syydelaervli kernel: [97580.341079] [] (sys_umoun= t+0x2bc/0x2e8) from [] (ret_fast_syscall+0x0/0x28) Other than that, the umount succeeded, I can mount the fs again and work on= that fs. This all with btrfs as it comes in 2.6.32. Ok, I guess that's it for now. cheers =2D- vbi =2D-=20 Leute, die immer nur mitfahren, sind stolz darauf, keine Unf=E4lle zu verschulden. -- Gabriel Laub --nextPart3737049.XsUg3xOSzW Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: get my key from http://fortytwo.ch/gpg/92082481 iKcEABECAGcFAks4x+NgGmh0dHA6Ly9mb3J0eXR3by5jaC9sZWdhbC9ncGcvZW1h aWwuMjAwMjA4MjI/dmVyc2lvbj0xLjUmbWQ1c3VtPTVkZmY4NjhkMTE4NDMyNzYw NzFiMjVlYjcwMDZkYTNlAAoJECqqZti935l6joYAn1Xqw1SxqFUIuOUUjGBmhtUV RAtlAJ9IXPAtQnqE7nuPMF+99+PGnY9oqQ== =6Bz3 -----END PGP SIGNATURE----- --nextPart3737049.XsUg3xOSzW--