Filesystem advice

Filesystem advice

[Volker Aßmann]

Hi!

Sorry if this post is a bit off-topic for this mailing list, but this
seams to be the best place to ask. We are currently using an embedded
linux system with a compact flash drive and ext3 as a filesystem. Due
to frequent power failures, we are often experiencing filesystem
corruption problems, and thus want to replace this setup with a better
option. My options / questions:

1. Replace ext3 with UBIFS or JFFS2 using the MTD-Blockdevice
emulation layer. Would this setup improve the reliability of our
system with respect to power failures, and if yes which is better
suited? Of course this approach would not improve the wear leveling,
but would it make it worse / probably confuse the integrated flash
controller?

2. Replace the Compact Flash module with an MTD device - this option
poses the problem that we can only deploy new hardware which is
connected through USB or the Compact Flash interface. I didn't find
any hardware which would support this setup - does something like this
exist?

3. In case both solutions are not viable, could you give an educated
guess on which traditional filesystem would be better suited for this
use case than ext3?

Thanks in advance and cheers,


      Volker Aßmann

Re: Filesystem advice

[Alexander Clouter]

Volker Aßmann <volker.assmann@googlemail.com> wrote:
> 
> Sorry if this post is a bit off-topic for this mailing list, but this
> seams to be the best place to ask. We are currently using an embedded
> linux system with a compact flash drive and ext3 as a filesystem. Due
> to frequent power failures, we are often experiencing filesystem
> corruption problems, and thus want to replace this setup with a better
> option. My options / questions:
> 
> 1. Replace ext3 with UBIFS or JFFS2 using the MTD-Blockdevice
> emulation layer. Would this setup improve the reliability of our
> system with respect to power failures, and if yes which is better
> suited? Of course this approach would not improve the wear leveling,
> but would it make it worse / probably confuse the integrated flash
> controller?
>
....I always found mounting with 'sync' plus 'ro' in places that I could 
(along with liberal use of tmpfs) made for a very reliable setup.  That 
was for ext3.
 
I would be inclined to look at nilfs2 as it sounds like the type of 
thing you would be looking for?

> 3. In case both solutions are not viable, could you give an educated
> guess on which traditional filesystem would be better suited for this
> use case than ext3?
> 
Alot of corruption can be due to braindead userland expectations.  
Generally this means the userland tools need to learn about fsync().

Cheers

-- 
Alexander Clouter
.sigmonster says: Walk softly and carry a megawatt laser.