hi ya brad
On Wed, 5 Jan 2005, Brad Campbell wrote:
Alvin Oga wrote:
for swap ... i personally don't see any reason to mirror
swap partitions ...
- once the system dies, ( power off ), all temp
data is useless unless one continues from a coredump ( from the same state as when it went down initially )
I beg to differ on this one. Having spend several weeks tracking down random processes dying on a machine that turned out to be a bad sector in the swap partition, I have had great results by running swap on a RAID-1. If you develop a bad sector in a non-mirrored swap, bad things happen indeterminately and can be a royal PITA to chase down. It's just a little extra piece of mind.
okay .... if the parts of disks is bad that is used for swap, mirroring might help ...
but, i wonder, how/why the system used that portion of swap in the first place - even for raid, if sector-10 in swap is bad, why would raid keep trying to write there instead of to sector-1000
Picture lpd gets swapped out on a friday night. Over the weekend it is not used and the drive develops a bad sector in the middle of the file. Monday morning I want to print and the system tries to page lpd back in again. *boom*.
I have not looked at the system swap algorithms, but I doubt they include automatic bad block management and read after write verification. I'm making big assumptions here, but I'm assuming they rely on a bad block table created by mkswap and an otherwise clean, functioning swap area.
Regards, Brad - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
