[plug] Don't do that!

Brad Campbell brad at wasp.net.au
Fri Sep 17 12:35:03 WST 2004


Bernd Felsche wrote:
> On Thursday 16 September 2004 12:10, Brad Campbell wrote:
> 
>>Bernd Felsche wrote:
>>
>>>building a filesystem on them. I'm not mirroring swap, instead
>>>assigning equal-priority swap partitions on both drives and letting
>>>the kernel handle the striping.
> 
> 
>>Why not? You go to the trouble of mirroring all the data, but if
>>you lose a disk with some allocated swap space on it the machine
>>*will* die a horrid death.
> 
> 
> And reboot 120 seconds later, being only able to access half the
> swap space and lose the LVm scratch space...  Not much of an issue.

Unfortunately, No.
It may just hang or corrupt user space processes. If it does panic and reboot, it will come back up 
with the full compliment of swap and the process will repeat itself. The kernel does not mark swap 
partitions to not be used if they develop bad sectors, it just blindly stumbles on hoping to regain 
its memory.

Been there, got the T-Shirt. It took me 3 months to figure out why certain processes would randomly 
die in odd ways or just hang and lock up.

At least with RAID-1, the partition with the bad sectors will be marked faulty and not re-used 
when/if the machine ever gets rebooted but in the mean while will not affect the operation of the box.

Don't get me wrong, I'm very grateful your doing what your doing, I'm just trying to point out a 
couple of bits that have bitten me over the years.

Regards,
Brad



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