I recently had a corrupted ext4 file system throwing these errors:
kubuntu@kubuntu:~$ sudo mount -t ext4 /dev/sdc2 c1 mount: wrong fs type, bad option, bad superblock on /dev/sdc2, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so kubuntu@kubuntu:~$ sudo fsck.ext4 -v /dev/sdc2 e2fsck 1.42.5 (29-Jul-2012) fsck.ext4: Attempt to read block from filesystem resulted in short read while trying to open /dev/sdc2 Could this be a zero-length partition? kubuntu@kubuntu:~$ dmesg | tail [ 2684.532855] Descriptor sense data with sense descriptors (in hex): [ 2684.532858] 72 03 11 04 00 00 00 0c 00 0a 80 00 00 00 00 00 [ 2684.532876] 05 3f c8 b0 [ 2684.532885] sd 5:0:0:0: [sdc] [ 2684.532893] Add. Sense: Unrecovered read error - auto reallocate failed [ 2684.532898] sd 5:0:0:0: [sdc] CDB: [ 2684.532902] Read(10): 28 00 05 3f c8 b0 00 00 08 00 [ 2684.532917] end_request: I/O error, dev sdc, sector 88066224 [ 2684.532927] Buffer I/O error on device sdc2, logical block 22 [ 2684.532973] ata6: EH complete
After recovering the partition with
e2fsck -f -b 32768, I've noticed that the oldest files on the disk were mostly preserved, and that most of the unrecovered files were the newest files, and thus without backups.
Is the property of losing the newest files and preserving the oldest files intrinsic to ext4, or was this just bad luck? Are there any file systems which, upon corruption, tend to lose the older files and to preserve the newer ones?