Re: checksum error...

["Scott E. Blomquist" <sb@techsquare.com>]

Hugo Mills writes:
 > On Mon, Apr 08, 2019 at 11:48:03AM -0400, Scott E. Blomquist wrote:
 > > 
 > > Hi All,
 > > 
 > > The weekend btrfs scrub/balance came back with this following...
 > > 
 > > [Sun Apr  7 06:57:10 2019] BTRFS warning (device sdb1): checksum error at logical 274820497408 on dev /dev/sda1, sector 536758784, root 271471, inode 109421914, offset 491520, length 4096, links 1 (path: yyyy/yyyyy)
 > [snip]
 > 
 >    Since there doesn't seem to be anything else wrong (no messages
 > without a filename, which would imply metadata corruption), this is
 > most likely a simple case of on-device corruption.
 > 
 >    Delete yyyy/yyyyy and restore it from backups. At least, do so in
 > the working copy; The snapshots of it can safely remain until they get
 > rotated out normally.
 > 
 >    Check your SMART statistics and see if anything looks wrong there
 > on the hardware side. Also check dmesg and earlier kernel logs for
 > signs of the hardware showing an error on read -- it may have tried
 > several times to read that location before giving up and/or returning
 > bad data.
 > 
 >    Hugo.

Thanks, Hugo.  Very helpful.

Turns out event log from MegaCli is showing some unexpected sense in
the eventlog.

Cheers,

sb. Scott Blomquist