Most controllers support a background-scrub that will read a volume
and repair any bad stripes. This addresses the bad block issue in
most cases.
It still doesn't help when a double-failure occurs. Luckily, that's
very rare. Usually, in that case, you need to evacuate the volume
and try to restore what was damaged.
On Jun 26, 2006, at 6:40 PM, Eric Schrock wrote:
On Mon, Jun 26, 2006 at 05:26:24PM -0600, Gregory Shaw wrote:
You're using hardware raid. The hardware raid controller will
rebuild
the volume in the event of a single drive failure. You'd need to
keep
on top of it, but that's a given in the case of either hardware or
software raid.
True for total drive failure, but not there are a more failure modes
than that. With hardware RAID, there is no way for the RAID
controller
to know which block was bad, and therefore cannot repair the block.
With RAID-Z, we have the integrated checksum and can do combinatorial
analysis to know not only which drive was bad, but what the data
_should_ be, and can repair it to prevent more corruption in the
future.
- Eric
--
Eric Schrock, Solaris Kernel Development http://blogs.sun.com/
eschrock
-----
Gregory Shaw, IT Architect
Phone: (303) 673-8273 Fax: (303) 673-8273
ITCTO Group, Sun Microsystems Inc.
1 StorageTek Drive MS 4382 [EMAIL PROTECTED] (work)
Louisville, CO 80028-4382 [EMAIL PROTECTED] (home)
"When Microsoft writes an application for Linux, I've Won." - Linus
Torvalds
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
