Re: file coruption on power fail

[Seth Mos <knuffie@xs4all.nl>]

At 15:12 25-3-2002 +0200, Ivan Ivanov wrote:
>I started testing XFS from kernel 2.4.6, the last was 2.4.18.
>Compiler is gcc-2.95-3 / Slackware-8.0
>Old machine - AMD K6, VIA TX Pro, WD Caviar UDMA HDD, 160 MB SDRAM.
>I have no any hardware problems. Machine doesn't crashes - I am unpluging
>power for testing. No kernel oops or somthing else.
>
>The main problem is not that data writen in last 30 sec. is lost - it is
>normal. The BIG PROBLEM is that entire file is lost. In the case with
>XF86Config I unpluged power during X startup. XF86Config must be opened ro
>but after rebooting it was garbage. Most of config files of X apps are
>broken ( in my case DFM configs ) if power crashes in a X session. Any
>file opened for editing with mcedit or any editor that rewrites file on 
>save is
>filled with NULL.
>Mounting filesystem with -o sync has no efect.

Mounting the filesytem sync should make this go away, also the latest CVS 
has a update which may fix this. Can try checking out the latest tree and 
see if this helps?

>This never hapens with ext3 in ordered data mode.
>
>So, is it a bug or a feature of XFS jornaling filesystem.

It is a feature present in all XFS enabled kernels before a recent 
2.4.18-xfs from CVS or recent split patches. The new 1.1 release which is 
coming also has this fix.

Cheers

--
Seth
Every program has two purposes one for which
it was written and another for which it wasn't
I use the last kind.