Product manual

26 Barracuda 18FC Product Manual, Rev. B
When the RC bit is one, reallocations are disabled even if the ARRE or AWRE bits are one. The drive will still
perform data recovery actions within the limits defined by the Read Retry Count, Write Retry Count, and
Recovery Time Limit parameters. However, the drive does not report any unrecovered errors.
[1] Setting these retry counts to a value below the default setting could result in degradation of the unrecov-
ered error rate. For example, suppose the read/write recovery page has the RC bit = 0, the read retry
count set to 4, and the recovery time limit set to 450. A 4-block read command can take up to 149.3 msec
recovery time for each block and a maximum of 450 msec recovery for all four blocks. If either of these lim-
its is reached and a block has not yet been recovered, the command will end with Check Condition status
and an unrecoverable read error will be reported.
7.3 FC-AL system errors
Information on the reporting of operational errors or faults across the interface is given in the
Fibre Channel
Interface Manual
. The FCP 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
Fibre Channel 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 [1]
Maximum recovery time per
LBA (cumulative, msec)
Write retry count
[1]
Maximum recovery time per
LBA (cumulative, msec)
0 65.7 0 35.8
1 77.6 1 53.7
2 89.6 2 59.7
3 113.4 3 77.6
4 149.3 4 185.1
5 197.0 5 (default) 226.9
6 244.8
7 334.3
8 394.0
9 441.8
10 549.2
11 2,009.2
12 (default) 4,283.8