Re: Unaligned AIO/DIO

[Jens Axboe <jaxboe@xxxxxxxxxxxx>]

On 2011-06-01 16:33, Troels Arvin wrote:
> Hello,
> 
> Jens Axboe wrote:
>> The iometer like test
>> case you are using is meant to be used on a raw block device, not on a
>> file system.
> 
> OK, but how does one use fio with a raw device? Can you give an example of a job specification file for working with a raw block device?

To take your example:

[global]
bssplit=512/10:1k/5:2k/5:4k/60:8k/2:16k/4:32k/4:64k/10
rw=randrw
rwmixread=70
direct=1
size=10g
ioengine=libaio
iodepth=256
write_bw_log
write_lat_log
numjobs=6

[sda]
filename=/dev/sda

would run the workload in question directly on the raw sda device.

> And can that be done in a way which simulates parallel I/O (several
> processes/threads working simultaneously)?

For the above example, you have 6 processes doing random read/write
patterns with the 70/30 read/write mix and with the block sizes given.

-- 
Jens Axboe

--
To unsubscribe from this list: send the line "unsubscribe fio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html