On Aug 19, 2011, at 7:21 PM, Jeremy Chadwick wrote: > On Fri, Aug 19, 2011 at 04:50:01PM -0400, Dan Langille wrote: >> System in question: FreeBSD 8.2-STABLE #3: Thu Mar 3 04:52:04 GMT 2011 >> >> After a recent power failure, I'm seeing this in my logs: >> >> Aug 19 20:36:34 bast smartd[1575]: Device: /dev/ad2, 2 Currently unreadable >> (pending) sectors > > I doubt this is related to a power failure. > >> Searching on that error message, I was led to believe that identifying the >> bad sector and >> running dd to read it would cause the HDD to reallocate that bad block. >> >> http://smartmontools.sourceforge.net/badblockhowto.html > > This is incorrect (meaning you've misunderstood what's written there). > > Unreadable LBAs can be a result of the LBA being actually bad (as in > uncorrectable), or the LBA being marked "suspect". In either case the > LBA will return an I/O error when read. > > If the LBAs are marked "suspect", the drive will perform re-analysis of > the LBA (to determine if the LBA can be read and the data re-mapped, or > if it cannot then the LBA is marked uncorrectable) when you **write** to > the LBA. > > The above smartd output doesn't tell me much. Providing actual SMART > attribute data (smartctl -a) for the drive would help. The brand of the > drive, the firmware version, and the model all matter -- every drive > behaves a little differently.
Information such as this? http://beta.freebsddiary.org/smart-fixing-bad-sector.php -- Dan Langille - http://langille.org _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
