Re: getting tape speed with iostat or similar

[Craig Sanders <cas@taz.net.au>]

i've already sent this to duncan in private mail, but thought others here
might find it useful:



google[1] came up with this:

http://sourceware.org/systemtap/wiki/WSiostatSCSI

 "Linux doesn't provide I/O statistics for tape devices for printing by the
iostat command. Rather than beg your vendor to patch your kernel to do this,
let systemtap do some digging."



[1] http://www.google.com/linux?hl=en&lr=&q=%2Biostat+%2Btape&btnG=Search



systemtap is packaged for debian:

Package: systemtap
Priority: optional
Section: devel
Installed-Size: 2264
Maintainer: Eugeniy Meshcheryakov <eugen@debian.org>
Architecture: i386
Version: 0.0.20061202-1
Depends: libc6 (>= 2.3.6-6), libelf1, libgcc1 (>= 1:4.1.1-12), libglib2.0-0
(>= 2.12.0), libmysqlclient15off (>= 5.0.24-2), libpfm3-3.2, libstdc++6 (>=
4.1.1-12), sudo
Filename: pool/main/s/systemtap/systemtap_0.0.20061202-1_i386.deb
Size: 653470
MD5sum: 3807fc4ef56fb4cd028287b211a8bb1e
SHA1: 02754b7276391c6f3a5f1eaaec3ce3f50dec57f2
SHA256: b54cc07d4b2fc5f73511c0eb6c796940bdb7319993cc0a04a57d40fbeef27a2d
Description: instrumentation system for Linux 2.6
 The SystemTap project aims to produce a Linux tool that lets
 application developers and system administrators take a deeper look
 into a running kernel. It aims to exploit the capability of a fully
 open-source Linux target to go beyond performance measurements, and
 perhaps even serve as a programmable debugger.


craig

ps: apparently you need to recompile your kernel and enable the
'kprobes' kernel debugging option to get this to work.

-- 
craig sanders <cas@taz.net.au>           (part time cyborg)