6.7 Reliability
6.7.1 Contact Start Stop (CSS)
The drive is designed to withstand a minimum of 40,000 contact start/stop cycles at 40˚C with 13-25% rela-
tive humidity.
The drive is designed to withstand a minimum of 10,000 contact start/stop cycles at operating environment
conditions specified in 6.4, “Environment” on page 39.
6.7.2 Data Reliability
Probability of not recovering data ....... 1 in 10
13
bits read
ECC On-The-Fly correction, performed as a part of read channel function, recovers up to 12 symbols of
error in 1 sector. (1 symbol is 8 bits.)
6.7.3 Seek/ID Mis-compare Errors
A non-recoverable seek/ID mis-compare error is defined as a seek operation that cannot be corrected by
fixed disk error recovery procedure. Seek errors occurring for field format operations are considered to be
non-recoverable.
No drive has more than one non-recoverable seek/ID mis-compare error per 5 milion seek operations (1 in 5
x10
6
) when operated at the full range of voltage and environmental conditions.
Non-recoverable seek/ID mis-compare errors indicate a defective drive.
6.7.4 Equipment Errors
A recoverable equipment error is any error other than a seek/ID mis-compare error or read error that is
detected and corrected by the drive error recovery procedure. Examples are Write Fault, Drive Not Ready
and internal drive errors.
No drive has more than one recoverable equipment error per 10
8
reads, 10
6
writes or 10
6
seeks operations
when operated at the full range of voltage and environmental conditions.
Non-recoverable equipment errors indicate a defective drive.
6.7.5 Failure Prediction ( PFA / S.M.A.R.T.)
DDRS-3xxxx supports Informational Exceptions Control Page (1C) defined in SCSI-3. The function enables
the drive to report sense codes of FAILURE PREDICTION THRESHOLD EXCEEDED to the host
system.
The page 1C specifies enable/disable, reporting method, and report count.
In case the drive exceeded the failure prediction threshold, the drive returns Check Condition on any
command. Then, per specified reporting method in Mode Page 1C, 0/5D/00, 1/5D/00 or 6/5D/00 as sense
key/code/qualifire is sent to the host as a response of Request Sense command.
As the default, the function is enabled but no reporting of informational exception condition is made.
The details are described in 7.9.13, “Page 1C (Informational Exceptions Control)” on page 113.
Specification 43
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