Provided by: bpfcc-tools_0.29.1+ds-1ubuntu7_all 
      
    
NAME
       virtiostat - Trace VIRTIO devices input/output statistics. Uses Linux eBPF/bcc.
SYNOPSIS
       virtiostat [-h] [-T] [-D] [-d DRIVER] [-n DEVNAME] [INTERVAL] [COUNT]
DESCRIPTION
       This  tool  traces VIRTIO devices input/output statistics. It works in lower layer of VIRTIO base driver,
       so it could trace all the devices of VIRTIO family. For example, we can't get IO statistics of 9p-fs in a
       guest virtual machine by iostat command, but we can analyze IO statistics by virtiostat.   The  outputing
       result  shows In/Out SGs(scatter list operation) to represent positive correlation IOPS, and In/Out BW to
       represent throughput.
       Since this uses BPF, only the root user can use this tool.
REQUIREMENTS
       CONFIG_BPF and bcc.
OPTIONS
       -h     Print usage message.
       -T     Include a time column on output (HH:MM:SS).
       -D     Show debug infomation of bpf text.
       -d DRIVER
              Filter for driver name.
       -n DEVNAME
              Filter for device name.
       INTERVAL
              Print output every interval seconds.
       COUNT  Total count of trace in seconds.
EXAMPLES
       Trace virtio device statistics and print 1 second summaries, 10 times:
              # virtiostat 1 10
       Trace virtio block deivces only:
              # virtiostat -d virtio_blk
OVERHEAD
       This    traces    the    kernel     virtqueue_add_sgs,     virtqueue_add_outbuf,     virtqueue_add_inbuf,
       virtqueue_add_inbuf_ctx functions.  The rate of this depends on all the VIRTIO devices IOPS.
SOURCE
       This is from bcc.
              https://github.com/iovisor/bcc
       Also  look  in  the bcc distribution for a companion _examples.txt file containing example usage, output,
       and commentary for this tool.
OS
       Linux
STABILITY
       Unstable - in development.
AUTHOR
       zhenwei pi
SEE ALSO
       iostat(1), iftop(8), funccount(8)
USER COMMANDS                                      2021-02-15                                      virtiostat(8)