On 4/23/07, Kalpak Shah <kalpak@xxxxxxxxxxxxxx> wrote:
On Mon, 2007-04-23 at 02:16 +0530, Karuna sagar K wrote:
.....
The file system is looked upon as a set of blocks (more precisely
metadata blocks). We randomly choose from this set of blocks to
corrupt. Hence we would be able to overcome the deficiency of the
previous approach. However this approach makes it difficult to have a
replayable corruption. Further thought about this approach has to be
given.
Fill a test filesystem with data and save it. Corrupt it by copying a
chunk of data from random locations A to B. Save positions A and B so
that you can reproduce the corruption.
Hey, thats a nice idea :). But, this woundnt reproduce the same
corruption right? Because, say, on first run of the tool there is
metadata stored at locations A and B and then on the second run there
may be user data present. I mean the allocation may be different.
Or corrupt random bits (ideally in metadata blocks) and maintain the
list of the bit numbers for reproducing the corruption.
.....
The corrupted file system is repaired and recovered with 'fsck' or any
other tools; this phase considers the repair and recovery action on
the file system as a black box. The time taken to repair by the tool
is measured
I see that you are running fsck just once on the test filesystem. It
might be a good idea to run it twice and if second fsck does not find
the filesystem to be completely clean that means it is a bug in fsck.
You are right. Will modify that.
<snip>
......
State of the either file system is stored, which may be huge, time
consuming and not necessary. So, we could have better ways of storing
the state.
Also, people may want to test with different mount options, so something
like "mount -t $fstype -o loop,$MOUNT_OPTIONS $imgname $mountpt" may be
useful. Similarly it may also be useful to have MKFS_OPTIONS while
formatting the filesystem.
Right. I didnt think of that. Will look into it.
Thanks,
Kalpak.
>
> Comments are welcome!!
>
> Thanks,
> Karuna
Thanks,
Karuna
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