Todd Denniston wrote:
Simon Slater wrote, On 03/10/2008 06:37 PM:
G'day all,
This is an inconvenience that I would like to get to the
bottom of. I
have a PII 233MHz 512 MbRAM running FC6. All is fine until swap reaches
about 25% used then the system hangs. It will run for days with the
swap at 10-15%. My first thought was to run badblocks to see if that
was the problem, since it is an old drive, but couldn't find the swap
device with mount.
Been there, done that.
WARNING: before using badblocks in full rw mode on swap space, remember
two things:
1) some how you would have to convince mkswap to retake what ever label
is being used in /etc/fstab, or you would need to use a new label/device
name in /etc/fstab.
2) don't be using it for swap while checking it. :)
/sbin/swapon -s
will display which partitions/files are being used in the system for swap.
/sbin/swapoff -a
will turn swap off. probably should shut down any programs down that you
don't need so that you can get under 512MB, then badblocks (with full
read/write test and re-`mkswap -c` on it, or Use non-destructive
read-write mode) sounds like a reasonable thing.
If you find a single bad block, you should really be looking for new
hardware.
I have done the thing where you partition around the bad blocks, but it
only buys you a little time.
If I understand the man-page for mkswap the -c will print the bad block
locations, it says nothing of setting up swap to avoid them.
My questions are: what would cause this system to hang when the swap
file is used?;
[from experience I know] Bad blocks in swap cause errors that look
_just_ like failing ram. That is, programs just die, system locks up in
weird ways.
where is the swap file?;
Most times it is a swap partition, `/sbin/swapon -s` or `cat
/proc/swaps` will help here.
if in the VG, how do I umount it
to run badblocks?
/sbin/swapoff
Here is some output that may be useful.
Thanks.
Good luck.
You could make a new swap file ( man mkswap has all the details ) and
use it while you are attempting the repair of the old swap space.
Good luck.
John
