On Tue, Aug 07 2007, Joshua Root wrote:
> I can't figure out the right way to tell fio to replay a trace captured
> with blktrace. There don't seem to be any specific examples of this in
> the documentation or readily apparent on the web.
>
> Should "fio --name=replay --read_iolog=foo" do something useful,
> assuming foo is binary blktrace output? If not, what would a typical
> command line for trace replaying look like?
First you capture data with blktrace, then you output a sorted binary
file that fio can use. Ala:
# blktrace /dev/sdb
(ctrl-c when done). This produces sdb.blktrace.[0..N] files, depending
on how many CPUs you have. Then you have to use blkparse to sort and
prepare that data:
# blkparse sdb -d sdb.bin
This produces an sdb.bin file, which is what fio needs to replay. Then
you need to do something ala
# fio --name=replay --filename=/dev/sdb --direct=1 --read_iolog=sdb.bin
to replay that IO pattern.
-- Jens AxboeReceived on Wed Aug 08 2007 - 09:03:17 CEST
This archive was generated by hypermail 2.2.0 : Wed Aug 08 2007 - 09:30:02 CEST