mounted loopback device suddendly become read only

Hi,

I have a "strange" problem. I use an usb disk connected to my nas to make backups. I use backintime (rsync) and to use hard links to save disk space, I created a "sparse" file on this usb disk. Then I mount it as ext4 on loopback device.

I can browse this sparse file (as root) and create files.

However each time I run the backup job, after a couple of minutes, rsync outputs errors messages because the filesystem is read only. For some unexplained reason, the filesystem switch from rw to ro after writing some files on it. I can't see any reason for that. The drive is empty, 500 Mb, and the only file is the spare file (490 Mb) withe 6Mb used.

 

Are there any errors in your logs?

 

yes :

Code:

Oct 23 21:48:16 thierrybo-Aspire-7540 backintime (root): INFO: Lock
Oct 23 21:48:16 thierrybo-Aspire-7540 backintime (root): INFO: on process begins
Oct 23 21:48:16 thierrybo-Aspire-7540 backintime (root): INFO: [GnomePlugin.Systray.run]
Oct 23 21:48:16 thierrybo-Aspire-7540 backintime (root): INFO: [GnomePlugin.Systray.run] begin loop
Oct 23 21:48:16 thierrybo-Aspire-7540 backintime (root): INFO: Profile_id: 2
Oct 23 21:48:16 thierrybo-Aspire-7540 backintime (root): INFO: Compare with old snapshot: 20121022-210811-374
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Command "rsync -rtDH --links --no-p --no-g --no-o  --delete --delete-excluded  -i --dry-run --out-format="BACKINTIME: %i %n%L" --chmod=Du+wx  --exclude="/media/BACKUP" --exclude="/root/.local/share/backintime" --include="/etc/" --include="/root/" --exclude=".gvfs" --exclude=".cache*" --exclude="[Cc]ache*" --exclude=".thumbnails*" --exclude="[Tt]rash*" --exclude="*.backup*" --exclude="*~" --exclude="/root/Ubuntu One" --exclude=".dropbox*" --include="/etc/fstab" --include="/etc/fuse.conf" --include="/root/**" --exclude="*" / "/media/BACKUP/backintime/thierrybo-Aspire-7540/root/2/20121022-210811-374/backup/"" returns 0
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Create hard-links
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Command "find "/media/BACKUP/backintime/thierrybo-Aspire-7540/root/2/20121022-210811-374/backup/" -type d -exec chmod u+wx {} \;" returns 0
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Command "cp -aRl "/media/BACKUP/backintime/thierrybo-Aspire-7540/root/2/20121022-210811-374/backup/"* "/media/BACKUP/backintime/thierrybo-Aspire-7540/root/2/new_snapshot/backup/"" returns 0
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Command "find "/media/BACKUP/backintime/thierrybo-Aspire-7540/root/2/20121022-210811-374/backup/" -type d -exec chmod a-w {} \;" returns 0
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Command "chmod -R a+w "/media/BACKUP/backintime/thierrybo-Aspire-7540/root/2/new_snapshot"" returns 0
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Call rsync to take the snapshot
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Command "rsync -rtDH --links --no-p --no-g --no-o  --delete --delete-excluded  -v  --chmod=Du+wx  --exclude="/media/BACKUP" --exclude="/root/.local/share/backintime" --include="/etc/" --include="/root/" --exclude=".gvfs" --exclude=".cache*" --exclude="[Cc]ache*" --exclude=".thumbnails*" --exclude="[Tt]rash*" --exclude="*.backup*" --exclude="*~" --exclude="/root/Ubuntu One" --exclude=".dropbox*" --include="/etc/fstab" --include="/etc/fuse.conf" --include="/root/**" --exclude="*" / "/media/BACKUP/backintime/thierrybo-Aspire-7540/root/2/new_snapshot/backup/" 2>&1" returns 0
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Save config file
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Command "cp /root/.config/backintime/config /media/BACKUP/backintime/thierrybo-Aspire-7540/root/2/new_snapshot/backup/.." returns 0
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Save permissions
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Create info file
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Command "chmod -R a-w "/media/BACKUP/backintime/thierrybo-Aspire-7540/root/2/20121023-214816-593/backup"" returns 0
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Command "chmod -R a-w "/media/BACKUP/backintime/thierrybo-Aspire-7540/root/2/20121022-210811-374/backup/"" returns 0
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Remove backups older than: 20101023-000000
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] considered: ['20121023-214816-593', '20121022-210811-374']
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep all >= 20121022-000000-168 and < 20121024-000000-321
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20121023-000000-811 and < 20121024-000000-356
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20121022-000000-633 and < 20121023-000000-675
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20121021-000000-970 and < 20121022-000000-634
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20121020-000000-233 and < 20121021-000000-869
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20121019-000000-524 and < 20121020-000000-777
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20121018-000000-920 and < 20121019-000000-422
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20121017-000000-699 and < 20121018-000000-984
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20121021-000000-296 and < 20121029-000000-173
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20121014-000000-265 and < 20121022-000000-170
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20121007-000000-803 and < 20121015-000000-199
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20120930-000000-644 and < 20121008-000000-377
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20121001-000000-756 and < 20121101-000000-728
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20120901-000000-520 and < 20121001-000000-282
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20120801-000000-354 and < 20120901-000000-243
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20120701-000000-406 and < 20120801-000000-884
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20120601-000000-836 and < 20120701-000000-491
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20120501-000000-509 and < 20120601-000000-713
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20120401-000000-598 and < 20120501-000000-795
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20120301-000000-310 and < 20120401-000000-345
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20120201-000000-659 and < 20120301-000000-771
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20120101-000000-387 and < 20120201-000000-994
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20111201-000000-107 and < 20120101-000000-117
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20111101-000000-358 and < 20111201-000000-229
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20111001-000000-772 and < 20111101-000000-145
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20110901-000000-913 and < 20111001-000000-776
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20110801-000000-801 and < 20110901-000000-149
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20110701-000000-983 and < 20110801-000000-443
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20110601-000000-474 and < 20110701-000000-726
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20110501-000000-131 and < 20110601-000000-639
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20110401-000000-722 and < 20110501-000000-677
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20110301-000000-933 and < 20110401-000000-277
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20110201-000000-549 and < 20110301-000000-145
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20110101-000000-657 and < 20110201-000000-271
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20101201-000000-917 and < 20110101-000000-387
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20101101-000000-575 and < 20101201-000000-457
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep first >= 20120101-000000-334 and < 20130101-000000-240
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: [smart remove] keep snapshots: ['20121023-214816-593', '20121022-210811-374']
Oct 23 21:48:17 thierrybo-Aspire-7540 backintime (root): INFO: Keep min free disk space: 1024 Mb
Oct 23 21:48:19 thierrybo-Aspire-7540 backintime (root): INFO: [GnomePlugin.Systray.run] end loop
Oct 23 21:48:19 thierrybo-Aspire-7540 backintime (root): INFO: Unlock
Oct 23 21:52:34 thierrybo-Aspire-7540 kernel: [ 9959.392176] EXT4-fs (loop0): error count: 18
Oct 23 21:52:34 thierrybo-Aspire-7540 kernel: [ 9959.392187] EXT4-fs (loop0): initial error at 1350506902: ext4_init_inode_table:1336
Oct 23 21:52:34 thierrybo-Aspire-7540 kernel: [ 9959.392196] EXT4-fs (loop0): last error at 1351021247: ext4_journal_start_sb:296: inode 11665580: block 46670027
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336114] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336148] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336171] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336191] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336211] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336228] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336245] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336263] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336280] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336295] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336310] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336323] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336337] CIFS VFS: No writable handles for inode
Oct 23 21:54:20 thierrybo-Aspire-7540 kernel: [10065.336349] CIFS VFS: No writable handles for inode

 

That sounds as if there is a problem with your hard disk (bad sectors or stuff like that). That would explain why it switches to read-only mode.