Chapter 14. Copy Services for the DS6000 473
contamwrts Specifies the Number of Contaminating writes for a Concurrent
Copy or XRC volume.
PPRCtrks Specifies the Number of tracks or portion of tracks that were
transferred to the secondary device of a PPRC pair.
NVSspallo Specifies the NVS Space Allocations.
timephread Specifies the Physical Storage Read Response Time in 16 ms
increments.
timephwrite Specifies the Physical Storage Write Response Time in 16 ms
increments.
byteread Specifies the number of Bytes read in 128 KB increments.
bytewrit Specifies the number of Bytes written in 128 KB incremnts.
timeread Specifies the accumulated response time for all read operations.
timewrite Specifies the accumulated response time for all write operation
Example 14-2 Counters displayed with showrank -metrics command
Counter Name Content
byteread Specifies Bytes Read
bytewri t Specifies Bytes Written
Reads Specifies Read Operations
Writes Specifies Write Operations
timeread Specifies Rank Read Response Time
timewrite Specifies Rank Write Response Time
Example 14-3 Counters displayed with showioport -metrics command
Counter Name Content
byteread (FICON/ESCON) ECKD Bytes Read
bytewrit (FICON/ESCON) ECKD Byte Writes
Reads (FICON/ESCON) ECKD Read Operations
Writes (FICON/ESCON) ECKD Write Operations
timeread (FICON/ESCON) ECKD Accumulated Read Time
timewrite (FICON/ESCON) ECKD Accumulated Write Time
bytewrit (PPRC) PPRC Bytes Send
byteread (PPRC) PPRC Bytes Received
Writes (PPRC) PPRC Send Operations
Reads (PPRC) PPRC Received Operations
timewrite (PPRC) PPRC Send Time Accumulated
timeread (PPRC) PPRC Received Time Accumulted
byteread (SCSI) SCSI Bytes Read
bytewrit (SCSI) SCSI Bytes Write
Reads (SCSI) SCSI Read Operations
Writes (SCSI) SCSI Write Operations
timeread (SCSI) SCSI Read Accumulated Time On Channel
timewrite (SCSI) SCSI Write Accumulated Time On Channel
14.11.1 Managing performance with DS CLI
The showrank -metrics output is a good place to begin to monitor your storage subsystem’s
performance. If you can maintain a database with the deltas of these counters, you have a
good basis to spot any significant changes from normal processing. Plan to save these base
counters for the same busy time period each day, and review the delta changes each week.
This discipline will build up an understanding of how your storage subsystem is performing,
and trends or significant changes should provide an early alert for possible I/O processing
bottlenecks.
474 IBM TotalStorage DS6000 Series: Performance Monitoring and Tuning
You can then monitor the logical disks that were defined in each suspect Rank using the
deltas from successive showckdvol -metrics or showfbvol -metrics commands to find which
volume is causing the Rank imbalance.
You should also periodically monitor traffic through your host I/O adapters with the showrank
-metrics command, so that you can identify increases in I/O.

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