HP StorageWorks Command View SDM Installation and User Guide (T1086-96023, February 2005)

Command Line User Interface 177
Command Line User Interface
Read ECC Usage DISK-PORTS Specifies the counter that counts the total number of retries
of the number of times the retry algorithm is invoked. If
after five attempts an error of type "Corrected Read Error
With Retry" is recovered, then five is added to this counter.
If three retries are required to get a stable ECC syndrome
before an error of type "Corrected Read Errors With
Delay" is corrected, then those three retries are also
counted here. The number of retries applied to
unsuccessfully recover an error of type "Total Uncorrected
Read Errors" are also counted by this counter.
Usage
Each of the read error counters provides a general
indication of the quality of read operations. Any
significant counts in any of the read error counters is an
indication that drive operational quality may be having an
effect on performance.
Read Rate (1.05 release)
Read Throughput (prior to 1.05)
ARRAY
LUN
The average number of host read commands completed
per second.
Usage
This metric is a measure of the performance level being
achieved for reads and also provides some indication of
the demand level of the host workload. High read rates
will not be achieved when the workload demand is low.
Read Throughput (1.05 release)
MBytes Read Throughput (prior to
1.05)
ARRAY
LUN
The average number of megabytes transferred per second
by read commands.
Usage
This metric is a measure of the performance level being
achieved for reads and also provides some indication of
the demand level of the host workload. High read
throughput will not be achieved when the workload
demand is low. This metric is computed from the Logical
Blocks Read Rate by converting logical blocks to
megabytes. The conversion factor is 2048 blocks per
megabyte.
Table 12 Performance Metrics (Continued)
Metric Categories Description/Usage