Re: RAID5 crash and burn

[Nathan Dietsch <njd@ndietsch.com>]

Hello Corey,

coreyfro@coreyfro.com wrote:

>Ahhhhhh... doesn't use the raidtab... nothing needs raidtab anymore... i
>guess its time i got with the program...
>
>About swap failing, would there be much of a performence hit if i mirrored
>swap?  
>  
>
 From what I read earlier in the thread, you already have a swap 
partition on software RAID5, so how would going to RAID1 hurt performance.?
With swap on RAID5 -- unless you are paging very heavily (enough for a 
full-stripe write) -- it seems you would go into Read-Modify-Write 
anyway and this will hurt ... badly.

Mirroring swap is a good idea to avoid crashes as Guy suggests.
If you are seriously considering the performance implications of RAID1 
vs RAID5 for swap, you are already done for performance wise.

Personally I would not consider software RAID5 suitable for tasks which 
require performance. An exception would be for heavy I/O that causes 
full-stripe writes, in which case you would probably get a win out of 
the extra disks.

I hope this helps.

Kind Regards,

Nathan Dietsch