-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Philip, On 12/24/2011 05:07 AM, Philip Hands wrote: [...] > Last night I started a check of the RAID that contained most of the errors on > that disk, and it's pretty much finished (81%), in which time the Pending > sector count is back up to 53. [Erm, 83% and 54 now -- while writing > this mail] > > Clearly it's not a particularly happy drive, so I guess that smart will > eventually diagnose it as faulty, but in the mean time it may be a > useful test case for mdadm. > > One of those newly pending sectors was found almost immediately, as I > was able to see from the logs, and while that was being dealt with, it > drove the system load up to about 18, and rendered the system > unresponsive for at least 10 seconds, probably more like 20 or 30 (the > normal load once it had chance to settle down again was about 2, on a 6 > core CPU, so it wasn't really that busy). > > [84% and 55 pending now -- with the first indication being a spike in > load, followed a minute or two later by mention of the read problems in > the logs, but apparently nothing logged by md, so presumably the read > eventually succeeded] > >> I wonder if a patch might be possible that allows one to put an array >> into a mode (or go into said mode once a badblock condition has >> happened) that causes it to read from at least 2 possible data sources >> and return whichever gets there first... > > Well, given that something appears to be blocking in a fairly > disastrous way on the read that's not coming back, I was wondering if > there might be some way of having a timeout on those reads that if one > gets no response for long enough (say 10 seconds) reacts by getting the > data from elsewhere, and overwriting the slow sector. Have you set up TLER or SCTERC on these drives? I suspect you haven't, as these long delays on read errors are typical of default error handling on consumer drives. Can you show the complete "smartctl -x" output for this failing drive? Phil -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk714VwACgkQBP+iHzflm3BXmACffzNuNvh98KueHKUL06e9Ultj ETcAn20P84PxbN3n6K0BlDoNsMpg1+2n =2gBn -----END PGP SIGNATURE----- -- 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
