NAME

       nfsiostat - Emulate iostat for NFS mount points using /proc/self/mountstats

SYNOPSIS

       nfsiostat [[<interval>] [<count>]] [<options>][<mount_point>]

DESCRIPTION

       The nfsiostat command displays NFS client per-mount statisitics.

       <interval>
              specifies  the  amount  of  time  in seconds between each report.  The first report
              contains statistics for  the  time  since  each  file  system  was  mounted.   Each
              subsequent  report  contains  statistics  collected  during  the interval since the
              previous report.

       <count>
              If the <count> parameter is specified, the value of <count> determines  the  number
              of  reports  generated  at  <interval>  seconds apart. if the interval parameter is
              specified  without  the  <count>   parameter,   the   command   generates   reports
              continuously.

       <options>
              Define below

       <mount_point>
              If  one  or more <mount point> names are specified, statistics for only these mount
              points will be displayed.  Otherwise, all  NFS  mount  points  on  the  client  are
              listed.

       The meaning of each column of nfsiostat's output is the following:
               - op/s
                      This is the number of operations per second.
               - rpc bklog
                      This is the length of the backlog queue.
               - kB/s
                      This is the number of kB written/read per second.
               - kB/op
                      This is the number of kB written/read per each operation.
               - retrans
                      This is the number of retransmissions.
               - avg RTT (ms)
                      This  is  the  duration  from  the  time that client's kernel sends the RPC
                      request until the time it receives the reply.
               - avg exe (ms)
                      This is the duration from the time that NFS client does the RPC request  to
                      its  kernel  until the RPC request is completed, this includes the RTT time
                      above.
               - avg queue (ms)
                      This is the duration from the time the NFS client created the  RPC  request
                      task to the time the request is transmitted.
               - errors
                      This  is  the  number  of  operations  that  completed with an error status
                      (status < 0).  This count is only available on  kernels  with  RPC  iostats
                      version 1.1 or above.

       Note  that  if  an  interval  is  used  as  argument to nfsiostat, then the diffrence from
       previous interval will be displayed, otherwise the results will be from the time that  the
       share was mounted.

OPTIONS

       -a  or  --attr
              displays statistics related to the attribute cache

       -d  or  --dir
              displays statistics related to directory operations

       -h  or  --help
              shows help message and exit

       -l LIST or  --list=LIST
              only print stats for first LIST mount points

       -p  or  --page
              displays statistics related to the page cache

       -s  or  --sort
              Sort NFS mount points by ops/second

       --version
              show program's version number and exit

FILES

       /proc/self/mountstats

SEE ALSO

       iostat(8), mountstats(8), nfsstat(8)

AUTHOR

       Chuck Lever <chuck.lever@oracle.com>

                                           15 Apr 2010                               nfsiostat(8)