On Thu, Dec 2, 2010 at 1:33 PM, Thomas Zander
<thomas.e.zan...@googlemail.com> wrote:
> Hi,
>
> do we have any way to monitor which LBAs of which block device are
> read/written at a given time?
>
> I stumbled upon this,
> http://southbrain.com/south/2008/02/fun-with-dtrace-and-zfs-mirror.html
>
> which is pretty intriguing. Unfortunately on FreeBSD we do not have
> the DTrace io provider, so his dtrace script would not work.
> Do we have another option to monitor block device access in a similar fashion?
GEOM sounds like a good candidate for probing of that kind.
sudo dtrace -n 'fbt:kernel:g_io_deliver:entry { printf("%s %d %d
%d\n",stringof(args[0]->bio_from->geom->name), args[0]->bio_cmd,
args[0]->bio_offset, args[0]->bio_length); }'
Keep in mind that g_io_deliver will be called for each GEOM node from
top to bottom for each completed request. You may need to add some
filtering on device name to avoid redundant info.
--Artem
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
