S
EAGATE
E
NTERPRISE
P
ERFORMANCE
10K HDD
V
7 P
RODUCT
M
ANUAL
, R
EV
. C
32
* For read retry count, every tick ~ 5% of total error recovery. Valid range setting is 1-20.
e.g. 1 ~ 5%
5 ~ 25%
20 ~ 100%
Setting these retry counts to a value below the default setting could result in degradation of the unrecovered error rate. For
example, suppose the read/write recovery page has the RC bit = 0 and if the read retry count is set to 5, this means ~ 25% of
error recovery will be executed which consumes 621.62 ms (please refer to the table above). If the limit is reached and a
LBA has not yet been recovered (i.e. requires retries beyond 621.62 ms), the command will end with Check Condition status
report and unrecoverable read error will be reported.
9.3
SAS
SYSTEM ERRORS
Information on the reporting of operational errors or faults across the interface is given in the
SAS Interface Manual
. The
SSP Response returns information to the host about numerous kinds of errors or faults. The Receive Diagnostic Results
reports the results of diagnostic operations performed by the drive.
Status returned by the drive to the initiator is described in the
SAS Interface Manual.
Status reporting plays a role in systems
error management and its use in that respect is described in sections where the various commands are discussed.
Table 2
Read and write retry count maximum recovery times
Read retry count*
Maximum recovery time per LBA
(cumulative, ms)
Write retry count
Maximum recovery time per LBA
(cumulative, ms)
0
35.94
1
124.32
1
53.91
5
621.62
2
79.89
10
1243.23
3
97.86
15
1864.85
4
175.85
20 (default)
2486.47
5 (default)
421.79
