[Gllug] JFS and bad blocks

[Martin A. Brooks]

Jack Bertram wrote:
> I can't seem to work out how to test a JFS filesystem for bad blocks and
> mark them bad. Anyone using it and can give advice?


I may be misunderstanding but what do bad blocks have to do with a 
filesystem?

All modern hard disks remap bad sectors on the fly.  This is (allegedly) 
one reason why manufacturers quote hard disk capacity as 10^n rather 
than 2^n.  The overhead gives them unused sectors to remap to.

If a disk had a bad block that's exposed to the host then the filesystem 
is irrelevant - all filesystems using the partition containing the bad 
block will be affected.

Perhaps you mean that you want to have the filesystem exclude writing to 
blocks that are known to be bad?  If so then you either have an old disk 
that doesn't do on-the-fly remapping or your disk has run out of sectors 
to remap to.  In either case you should seriously consider simply 
replacing the hard disk - they are stupidly cheap these days.

Or did I miss the point?

Mart.
-- 
Gllug mailing list  -  Gllug at gllug.org.uk
http://lists.gllug.org.uk/mailman/listinfo/gllug