Capturing I/O traces

[unixtools at hotmail.com]

Hi,

 To capture appication IO, the best option on freebsd is ktrace. I have no
idea how to trace all the io calls triggered by the kernel.

Sunil Sunder Raj
http://daemon.in


----- Original Message ----- 
From: "Fluffles" <etc at fluffles.net>
To: <freebsd-geom at freebsd.org>; <freebsd-fs at freebsd.org>
Sent: Tuesday, January 09, 2007 6:10 PM
Subject: Capturing I/O traces


> Hello list,
>
> I was wondering if any method is known to "capture" I/O traces. My goal
> is to be able to simulate I/O access patterns generated by applications
> such as MySQL or KDE and compare these to other storage systems. This
> way i can provide more realistic benchmarks (not synthetic) without
> actually running the application i'm testing. For example, I would like
> to capture the I/O that occurs when KDE boots, and then be able to
> reproduce this I/O access on say a gmirror and graid3. This way i can
> gather more realistic benchmark results. On Windows several commercial
> applications exist that 'simulate' access patterns used by applications,
> i was wondering if any BSD/Linux equivalent exists.
>
> One thought that comes to mind is the gnop geom class; with verbose mode
> this provides a text log of all the I/O accesses. But it does not
> provide the exact time/concurrency etc, only the offset, length, I/O
> action (read/write) and the serial order of those requests. And even
> with this information it's not easy to reproduce them; i would have to
> write an application that reads this log and then be able to reproduce
> it. I was hoping to find a more elegant solution. If you guys know of
> any, please share it with me. :)
>
> Regards,
>
> Veronica
> _______________________________________________
> freebsd-fs at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-fs
> To unsubscribe, send any mail to "freebsd-fs-unsubscribe at freebsd.org"
>