Re: I request inclusion of reiser4 in the mainline kernel

Ric Wheeler
2005-09-21T01:15:58Z

Gregory Maxwell wrote:
> On 9/20/05, Theodore Ts'o <tytso@mit.edu> wrote:
>
>>There is a very interesting paper that I coincidentally just came
>>across today that talks about making filesystems robust against
>>various different forms of failures of modern disk systems. It is
>>going to be presented at the upcoming 2005 SOSP conference.
>>
>> http://www.cs.wisc.edu/adsl/Publications/iron-sosp05.pdf
>
>
> Very interesting indeed, although it almost seems silly to tackle the
> difficult problem of making filesystems highly robust against oddball
> failure modes while our RAID subsystem falls horribly on it's face in
> the fairly common (and conceptually easy to handle) failure mode of a
> raid-5 where two disks have single unreadable blocks on differing
> parts of the disk. (the current raid system hits one bad block, fails
> the whole disk, then you attempt a rebuild and while reading hits the
> other bad block and downs the array).

I don't have any problem with fixing RAID code, but I would not describe
the errors in this paper as oddball. Believe me, we see a lot of disk
issues and these are real examples of failures that happen to real file
systems ;-)

Ric