Veritas™ Volume Manager Administrator's Guide

Displaying cumulative I/O statistics

Use the groupby clause of the vxdmpadm iostat command to display cumulative I/O statistics listings per DMP node, controller, array port id, or host-array controller pair and enclosure. If the groupby clause is not specified, then the statistics are displayed per path.

To group by DMP node:

# vxdmpadm iostat show groupby=dmpnode [all | dmpnodename=dmpnodename 
| enclosure=enclr-name] 

To group by controller:

# vxdmpadm iostat show groupby=ctlr [ all | ctlr=ctlr ] 

For example:

# vxdmpadm iostat show groupby=ctlr ctlr=c5

            OPERATIONS        BLOCKS       AVG TIME(ms)
CTLRNAME  READS   WRITES  READS  WRITES  READS   WRITES
c5 	      224      14     54      7       4.20 	  11.10

To group by arrayport:

# vxdmpadm iostat show groupby=arrayport [ all | pwwn=array_pwwn
 | enclosure=enclr portid=array-port-id ]

For example:

# vxdmpadm iostat show groupby=arrayport enclosure=HDS9500-ALUA0 \
portid=1A 	             

            OPERATIONS        BLOCKS       AVG TIME(ms)
PORTNAME  READS   WRITES  READS  WRITES  READS   WRITES
1A 	      224      14     54      7       4.20 	  11.10

To group by enclosure:

# vxdmpadm iostat show groupby=enclosure [ all | enclosure=enclr ] 

For example:

# vxdmpadm iostat show groupby=enclosure enclosure=EMC_CLARiiON0

               OPERATIONS       BLOCKS       AVG TIME(ms)
ENCLRNAME    READS  WRITES  READS  WRITES  READS   WRITES
EMC_CLARiiON	0		    0		     0	     0	       0.00     0.00

You can also filter out entities for which all data entries are zero. This option is especially useful in a cluster environment which contains many failover devices. You can display only the statistics for the active paths.

To filter all zero entries from the output of the iostat show command:

# vxdmpadm -z iostat show [all|ctlr=ctlr_name |
dmpnodename=dmp_device_name | enclosure=enclr_name [portid=portid] |
pathname=path_name|pwwn=port_WWN][interval=seconds [count=N]]

For example:

# vxdmpadm -z iostat show dmpnodename=c2t16d4

              OPERATIONS        BLOCKS        AVG TIME(ms)
PATHNAME   READS  WRITES    READS   WRITES  READS   WRITES
c3t16d4    10     110       2       25     	12.00    27.96
c2t17d4    20     126       4       29       9.50    19.41

You can now specify the units in which the statistics data is displayed. By default, the read/write times are displayed in milliseconds up to 2 decimal places. The throughput data is displayed in terms of 'BLOCKS' and the output is scaled, meaning that the small values are displayed in small units and the larger values are displayed in bigger units, keeping significant digits constant.The -u option accepts the following options:

For example: To display average read/write times in microseconds.

# vxdmpadm -u us iostat show pathname=c2t17d4

              OPERATIONS        BLOCKS        AVG TIME(microsec)
PATHNAME   READS  WRITES    READS   WRITES  READS     WRITES
c2t17d4  20     126       4       29    9500.00  19413.79