I am in the process of replacing some failing SATA disks with new SAS disks. The raid array that one of the failing disks is part of is in the process of resilvering. As that progresses, I can see the write error correction rate on the new disk slowly but steadily increase. This is my first exposure to SAS hardware, and I am unfamiliar with the smartctl output, since I'm used to the big table that SATA disks produce.
The disk is an HGST Ultrastar 2TB, attached through an IBM M1015 HBA, in passthrough mode.
How exactly should I interpret the SMART data below? Should the rising corrected-error rate worry me? What about the Correction Algorithm Invocations field?
Device: HITACHI HUS723020ALS640 Version: A222 Serial number: xxxxxxxx Device type: disk Transport protocol: SAS Local Time is: Thu Jul 11 15:42:30 2013 MDT Device supports SMART and is Enabled Temperature Warning Enabled SMART Health Status: OK Current Drive Temperature: 44 C Drive Trip Temperature: 85 C Manufactured in week 29 of year 2012 Recommended maximum start stop count: 50000 times Current start stop count: 2 times Elements in grown defect list: 0 Vendor (Seagate) cache information Blocks sent to initiator = 149833037905920 Error counter log: Errors Corrected by Total Correction Gigabytes Total ECC rereads/ errors algorithm processed uncorrected fast | delayed rewrites corrected invocations [10^9 bytes] errors read: 0 0 0 0 6 0.565 0 write: 0 400 0 400 51 1034.246 0 verify: 0 0 0 0 37 0.000 0 Non-medium error count: 0