You can monitor zFS performance using the MODIFY command. The output from the MODIFY ZFS,QUERY command is written to the system log. The syntax of this command and an explanation of the report and their option values, if any, are shown below.

KN

Provides counts of calls made to zFS from z/OS® UNIX and the average response time of each call. This information is the basic measure of zFS performance. See KN for details of the report.

VM

Provides performance information for the user file cache including cache hit ratios, I/O rates, and storage usage. See VM for details of the report.

LFS

Provides detailed file system statistics including the performance of the zFS metadata caches, the vnode cache, and the aggregate I/O statistics. See LFS for details of the report.

LOG

Provides performance information for the log file cache. See LOG for details of the report.

LOCK

Provides a measure of lock contention and how often z/OS UNIX threads wait for certain events such as user file cache reclaim. See LOCK for details of the report.

STOR

Provides a detailed breakdown of zFS allocated storage by component. By default, this report lists only storage usage by zFS component. If you use the DETAILS option, you get more detailed information for each zFS component. See STOR for details of the report.

FILE

Provides a detailed breakdown of requests per zFS file system and aggregate. By default, this report lists only file systems and aggregates that had active requests since the last statistics reset. If you use the ALL option, you get all file system and aggregates regardless of whether they were active or not. See FILE for details of the report.

STKM

Displays the current server token manager (STKM) statistics. See STKM for details of the report.

CTKC

Displays the client token manager statistics. CTKC is only present when the system is a Sysplex client of another system and the zFS ctkc component on this system sent a message to another system. See CTKC for details of the report.

IOBYDASD

Displays the I/O statistics by currently attached DASD volumes including the total number of waits for I/O and the average wait time per I/O. See IOBYDASD for details of the report.

DATASET

Displays zFS statistics about file systems.

SVI

Displays the server vnode interface (SVI) calls from other systems to this server. See SVI for details of the report. SVI will be present when the system is a server to another system and the zFS svi component on this system has received a message from another system.

ALL

Shows all the above reports. However, for the STOR report, the DETAILS option is off and the FILE report indicates only active file systems.