This article was posted to the Usenet group alt.hackers in
1995; any technical information is probably outdated.
a small hack
Article: 7941 of alt.hackers From: kim@mso.anu.edu.au Newsgroups: alt.hackers Subject: a small hack Date: 02 Jun 1995 21:43:57 +1000 Organization: Mount Stromlo and Siding Spring Observatories. Lines: 42 Approved: trent@NIN.com Message-ID: rhivqp0x36.fsf@magician.anu.edu.au NNTP-Posting-Host: 150.203.89.99 X-Newsreader: (ding) Gnus v0.79 Status: RO
Just a small (Ob)hack I performed today:
Needed to collect some disk i/o stats for a bunch of workstations.
Unfortunately the system supplied iostat command only printed out
stuff like:
extended disk statistics
disk r/s w/s Kr/s Kw/s wait actv svc_t %w %b
sd1 0.2 0.0 4.4 0.4 0.0 0.0 29.5 0 0
sd16 0.0 0.1 0.4 3.3 0.0 0.0 74.1 0 0
sd2 0.0 0.0 0.8 0.4 0.0 0.0 31.6 0 0
sd3 0.3 0.5 1.2 4.7 0.0 0.0 25.7 0 1
This is OK, but I need to average over a long time, so if a disk
isnt particularly active, the kB read and write numbers might
be only 0.1 or 0.2 - ie, very low precision, just one sig. fig.
No sources available of course. Solution:
'strings iostat', find the printf string in the executable which looks like
%-8.8s %4.1f %4.1f %6.1f %6.1f %4.1f %4.1f %6.1f %3.0f %3.0f
copy the binary, edit the string to say
%-8.8s %4.1f %4.1f %6.1f %6.1f %4.2f %4.2f %6.1f %3.0f %3.0f
Now my new improved iostat says:
extended disk statistics
disk r/s w/s Kr/s Kw/s wait actv svc_t %w %b
sd1 0.2 0.0 4.36 0.44 0.0 0.0 29.5 0 0
sd16 0.0 0.1 0.39 3.27 0.0 0.0 74.1 0 0
sd2 0.0 0.0 0.81 0.38 0.0 0.0 31.6 0 0
sd3 0.3 0.5 1.18 4.72 0.0 0.0 25.7 0 1
I was much happier.
Kim.
--
Kim Sebo
Mount Stromlo and Siding Spring Observatories, A.N.U.
Email: kim@mso.anu.edu.au or kms100@huxley.anu.edu.au
Phone: Work: +61 6 249-0253