On Sat, 22 Mar 2008, Theodore Tso wrote:
On Fri, Mar 21, 2008 at 06:35:43PM +0100, Peter Rabbitson wrote:
Of course it would be possible to instruct md to always read all
data+parity chunks and make a comparison on every read. The performance
would not be much to write home about though.
Yeah, and that's probably the real problem with this scheme. You
basically reduce the read bandwidth of your array down to a single
(slowest) disk --- basically the same reason why RAID-2 is a
commercial failure.
I don't really see this as a problem. Most of my filesystems are not
anywhere near their performance limit and reading a strip from the parity
disks as well as all the strips from the data disks in a raid6 setup
probably would be less than a 50% performance hit, so I would very much
appriciate a "paranoid parity check on every read" flag to set on _some_
of my raids.
/Mattias Wadenstein
--
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
