The following is a demonstration of the iofile.d script,


Here we run it while a tar command is backing up /var/adm,

   # iofile.d
   Tracing... Hit Ctrl-C to end.
   ^C
      PID CMD              TIME FILE
     5206 tar               109 /var/adm/acct/nite
     5206 tar               110 /var/adm/acct/sum
     5206 tar               114 /var/adm/acct/fiscal
     5206 tar               117 /var/adm/messages.3
     5206 tar               172 /var/adm/sa
     5206 tar              3605 /var/adm/messages.2
     5206 tar              4548 /var/adm/spellhist
     5206 tar              5769 /var/adm/exacct/brendan1task
     5206 tar              6416 /var/adm/acct
     5206 tar              7587 /var/adm/messages.1
     5206 tar              8246 /var/adm/exacct/task
     5206 tar              8320 /var/adm/pool
     5206 tar              8973 /var/adm/pool/history
     5206 tar              9183 /var/adm/exacct
        3 fsflush         10882 <none>
     5206 tar             11861 /var/adm/exacct/flow
     5206 tar             12042 /var/adm/messages.0
     5206 tar             12408 /var/adm/sm.bin
     5206 tar             13021 /var/adm/sulog
     5206 tar             19007 /var/adm/streams
     5206 tar             21811 <none>
     5206 tar             24918 /var/adm/exacct/proc

In the above output, we can see that the tar command spent 24918 us (25 ms)
waiting for disk I/O on the /var/adm/exacct/proc file.