On 2014-11-18 02:29, Brendan Hide wrote:
In addition to the storage controller being a possibility as mentioned in another reply, there are some parts of the drive that aren't covered by SMART attributes on most disks, most notably the on-drive cache. There really isn't a way to disable the read cache on the drive, but you can disable write-caching, which may improve things (and if it's a cheap disk, may provide better reliability for BTRFS as well). The other thing I would suggest trying is a different data cable to the drive itself, I've had issues with some SATA cables (the cheap red ones you get in the retail packaging for some hard disks in particular) having either bad connectors, or bad strain-reliefs, and failing after only a few hundred hours of use.Hey, guysSee further below extracted output from a daily scrub showing csum errors on sdb, part of a raid1 btrfs. Looking back, it has been getting errors like this for a few days now. The disk is patently unreliable but smartctl's output implies there are no issues. Is this somehow standard faire for S.M.A.R.T. output? Here are (I think) the important bits of the smartctl output for $(smartctl -a /dev/sdb) (the full results are attached): ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000f 100 253 006 Pre-fail Always - 0 5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 1 7 Seek_Error_Rate 0x000f 086 060 030 Pre-fail Always - 440801014 197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0010 100 100 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0000 100 253 000 Old_age Offline - 0 202 Data_Address_Mark_Errs 0x0032 100 253 000 Old_age Always - 0 -------- Original Message -------- Subject: Cron <root@watricky> /usr/local/sbin/btrfs-scrub-all Date: Tue, 18 Nov 2014 04:19:12 +0200 From: (Cron Daemon) <root@watricky> To: brendan@watricky WARNING: errors detected during scrubbing, corrected. [snip] scrub device /dev/sdb2 (id 2) done scrub started at Tue Nov 18 03:22:58 2014 and finished after 2682 seconds total bytes scrubbed: 189.49GiB with 5420 errors error details: read=5 csum=5415 corrected errors: 5420, uncorrectable errors: 0, unverified errors: 164 [snip]
smime.p7s
Description: S/MIME Cryptographic Signature
