Stress testing the UFS2 filesystem

[Kris Kennaway]

On Wed, May 03, 2006 at 12:32:29AM +0400, Pavel Merdine wrote:
> Hello ,
> 
> Thank you for raising this problem again. I already tried to do that
> in that list, but received an answer that kernel is intended to do
> that. For example, you have a faulty disk. And you have a faulty
> sector which happened to occur on the directory place. So each time
> kernel reads this sector it panics. So it's initially hard to even
> understand what happens. And also it leads to corruption and lost
> files on other file system (each time). Imagine if you have 15 disks.
> In this case you have many files lost just because of a small (and not
> significant) fault. It's just a nonsense.
> Personally, I just replaced bad_dir with error return.
> By the way, there was some bug in fs in kernel that could lead to
> panic even on clean filesystem (bad_dir as far as I remember). It is
> very rare and it was fixed on DragonFly. As far as I remember a fix
> for this was also commited to current recently.
> 
> I think that Linux is usually much smarter on this. By default it
> remounts a file system as read-only in case it detects a filesystem
> corruption. I would be very happy if FreeBSD could do the same,
> because fs panics really hurt when you have many systems with disks.
> 
> Of course I think we could do patches to overcome corrupting panics,
> but the core FreeBSD team would not accept this, as they are happy
> with panics and corruptions they make to other filesystems.

Of course not, don't make silly accusations :-)

The problem is much more difficult to solve than "making the panic an
error return".

Kris
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 187 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-fs/attachments/20060502/92cfa67c/attachment.pgp