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

AUTHOR¶

zhenwei pi

SEE ALSO¶

iostat(1), iftop(8), funccount(8)