Unrecovered read error on scsi drive

[Don Bowman]

> From: Don Bowman [mailto:don at sandvine.com]
> 
> I have a system which popped out this error after many [500?] hours
> of disk stress [swapping, dd]:
> 
> (da0:ahd0:0:0:0): READ(10). CDB: 28 0 0 c7 92 a0 0 0 28 0
> (da0:ahd0:0:0:0): MEDIUM ERROR info:c792bb asc:11,0
> (da0:ahd0:0:0:0): Unrecovered read error field replaceable unit: e4
> sks:80,86
> 
> However, it claims to have 0 defects:
> 
> # camcontrol defects 0:0:0 -f phys -G
> Got 0 defects.
> 
> How can this be? Are there other causes for this unrecovered 
> read error?

Sorry, i forgot to add, I have AWRE and ARRE enabled:

# camcontrol modepage 0:0:0 -m 1
AWRE (Auto Write Reallocation Enbld):  1
ARRE (Auto Read Reallocation Enbld):  1
TB (Transfer Block):  0
RC (Read Continuous):  0
EER (Enable Early Recovery):  0
PER (Post Error):  0
DTE (Disable Transfer on Error):  0
DCR (Disable Correction):  0
Read Retry Count:  11
Correction Span:  240
Head Offset Count:  0
Data Strobe Offset Count:  0
Write Retry Count:  5
Recovery Time Limit:  65535