Xfs_repair and journalling

[Martin Steigerwald]

Am Sonntag, 17. März 2013 schrieb Subranshu Patel:
> In case of EXT4, journal will not be replayed on performing mount. One
> need to invoke fsck which performs journal playback and then other
> corruption checks/recovery.
> Correct me if I am wrong.

USB stick with Ext4 without any mkfs options:

merkaba:~> mount /dev/sdb /mnt/zeit   
merkaba:~> rsync -a /etc /mnt/zeit    

(was to short)

merkaba:~> rsync -a /usr/bin /mnt/zeit

Unplug during write activity:



merkaba:~> grep "journal" /var/log/syslog | tail -5 
Mar 18 21:43:22 merkaba kernel: [29938.038298] journal commit I/O error
Mar 18 21:43:22 merkaba kernel: [29938.038300] journal commit I/O error
Mar 18 21:43:22 merkaba kernel: [29938.038302] journal commit I/O error
Mar 18 21:43:22 merkaba kernel: [29938.038305] journal commit I/O error
Mar 18 21:43:22 merkaba kernel: [29938.038308] journal commit I/O error
merkaba:~> grep -c "journal commit" /var/log/syslog
1915


Wait till KDE SC stops replaying these notifications and then restart 
plasma-desktop to get rid of it cause that takes to long.


Plug USB stick back in. And mount it:

merkaba:~> mount /dev/sdc /mnt/zeit 
merkaba:~> ls -l /mnt/zeit
insgesamt 40
drwxr-xr-x   2 root root 12288 Mär 18 21:43 bin
drwxr-xr-x 188 root root 12288 Mär 18 13:31 etc
drwx------   2 root root 16384 Mär 18 21:42 lost+found


Mount took about 5 seconds.


merkaba:~> dmesg | tail -2
[30217.601896] EXT4-fs (sdc): recovery complete
[30217.603287] EXT4-fs (sdc): mounted filesystem with ordered data mode. 
Opts: (null)


So can we get over any guess work that Ext4 might not be able to replay
its journal after an unclean shutdown?

It can and it does. And not just since this 3.9-rc3 kernel.

Thanks,
-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
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