I'm pleased to announce the first release of virt-top, which is a
top-like utility for displaying virtualization stats.
It aims to look and feel very much like regular 'top', so as to be as
familiar as possible for systems administrators. You can also use it as
a pleasant replacement for xentop.
It uses libvirt, so can display stats across a variety of different
hypervisors and virtualization systems (not just Xen, although that is
where the testing has gone so far).
The license is a combination of LGPL (for the library) and GPL (for the
You can view domains and use familiar keys like 'P'/'M'/... to sort by
processor/memory/..., and 'd'/'s' to set the delay between updates.
Also some common top command-line options are implemented. The man page
is here: http://et.redhat.com/~rjones/virt-top/virt-top.txt
There are a variety of source and binary RPMs available for Fedora
users. I don't yet have a working Debian/Ubuntu package, but will have
a go at making one tomorrow.
The next thing I'll be working on is showing virtual and physical CPU
usage of guests. After that I'm hoping to discuss extensions to libvirt
to make other interesting statistics available to virt-top, in
particular disk and network I/O stats.
There are a few data collection artifacts which need to be investigated.
In particular, %CPU sometimes goes over 100%. Obviously accurate data
collection is an important goal for this tool.
Memory usage is good: typical 'RES' (in regular top) for virt-top is
just under 2.5 MB, and I've had it running for hours at a time without
memory usage increasing, which seems to indicate that there aren't any
major memory leaks.
The program is currently very small: exactly 500 lines of code!
If you want to dive in and send me patches they are most welcome, but
remember that I'm trying to make this utility act as much like 'top' as
possible, so if 'top' does it in a particular way, then I'd prefer
virt-top to do the same thing. (May not apply to obscure top
functionality, if top does something silly).
If you're a systems administrator, not a programmer, and you'd like
virt-top to have some particular feature, then please let me know, and I
will be happy to review it and code it for you.
Emerging Technologies, Red Hat - http://et.redhat.com/~rjones/
Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod
Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in
England and Wales under Company Registration No. 03798903