ESS

   .-NOESS------------------.   
>>-+------------------------+----------------------------------><
   '-ESS-+----------------+-'   
         |   .-,------.   |     
         |   V        |   |     
         '-(---option-+-)-'     

Specifies whether Enterprise Disk System statistics should be gathered. The gathered data is stored in SMF records type 74 subtype 8.

If you specify option, this can be one or more of the following:

LINK

link performance statistics are gathered.

RANK

extent pool statistics and rank statistics are gathered.

NOLINK

no link performance statistics are gathered.

NORANK

no extent pool and rank statistics are gathered.

If you do not specify neither the LINK nor the RANK option, then both LINK and RANK are default.

As ESS data gathering involves cache activity measurement (see option CACHE), it is recommended to specify both options in common. If you specify ESS together with NOCACHE, cache data is gathered implicitly without writing SMF 74 subtype 5 records.

In a sysplex, options CACHE and ESS can be specified on any system sharing the measured devices. Therefore specify options ESS and CACHE together on one selected system only to avoid duplicate data gathering.