On 12/06/14 16:06, Roman Mamedov wrote:
In one case which Brad was describing, it was a hardware design fault
in his RAID controller, resulting in it returning bad data only when
all ports are utilized at high speeds. If MD had online checksum
mismatch detection, it would alert him immediately that something's
going wrong, rather than have this bug happily chew through all his
data, with "months of read/modify/write cycles combined with corrupt
data spread the corruption all over the array".
Yeah, you are right it would have possibly spared some of my data.
Having said if I'd been paying attention to the mismatch counts at the
end of my monthly scrubs I'd have noticed it a _lot_ sooner also. I had
the tools, I was just not using them right. My fault, not md's.
Having said that, if I'd not gone through that I'd probably still not
have comprehensive and complete backups, and I'd not have
developed/found tools to allow me to better monitor my systems. So while
it was a painful experience, it was not catastrophic and (as Calvin's
dad would say) it built some more character.
I'm a lot older, and hopefully wiser from the experience. I also know my
time is better spent with monitoring and backups than developing code to
build that feature into md. While that would paper over one part of the
storage chain, backups and monitoring covers me end to end.
--
Dolphins are so intelligent that within a few weeks they can train
Americans to stand at the edge of the pool and throw them fish.
--
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
