Re: I/O and pdflush

[Fernando Silveira]

On Mon, Aug 31, 2009 at 11:07, Wu Fengguang<fengguang.wu@xxxxxxxxx> wrote:
> On Mon, Aug 31, 2009 at 10:01:13PM +0800, Wu Fengguang wrote:
>> On Mon, Aug 31, 2009 at 10:00:06PM +0800, Wu Fengguang wrote:
>> > Hi Fernando,
>> >
>> > What's your SSD's IO parameters? Ie. output of this command:
>> >
>> >         grep -r . /sys/block/sda/queue/
>> >
>> > Please replace 'sda' with your SSD device name.
>>
>> Oh I guess it's sdc:
>>
>>          grep -r . /sys/block/sdc/queue/

Here is it:

# grep -r . /sys/block/sdc/queue/
/sys/block/sdc/queue/nr_requests:128
/sys/block/sdc/queue/read_ahead_kb:128
/sys/block/sdc/queue/max_hw_sectors_kb:128
/sys/block/sdc/queue/max_sectors_kb:128
/sys/block/sdc/queue/scheduler:noop anticipatory [deadline] cfq
/sys/block/sdc/queue/hw_sector_size:512
/sys/block/sdc/queue/rotational:0
/sys/block/sdc/queue/nomerges:0
/sys/block/sdc/queue/rq_affinity:0
/sys/block/sdc/queue/iostats:1
/sys/block/sdc/queue/iosched/read_expire:500
/sys/block/sdc/queue/iosched/write_expire:5000
/sys/block/sdc/queue/iosched/writes_starved:2
/sys/block/sdc/queue/iosched/front_merges:1
/sys/block/sdc/queue/iosched/fifo_batch:16
#

These are probably default settings.

> BTW, would you run "iostat -x 1 5" (which will run 5 seconds) when
> doing I/O in ideal throughput, and when in 25MB/s thoughput state?

Both files are attached (25mbps = 25MB/s, 80mbps = 80MB/s).

Thanks.

-- 
Fernando Silveira <fsilveira@xxxxxxxxx>

Attachment: log-20090831_0908-MK020903042C0001B-prosar_fcc2-bs_4M-0-iostat_x_1_5-80mbps_3.log
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Attachment: log-20090831_0908-MK020903042C0001B-prosar_fcc2-bs_4M-0-iostat_x_1_5-25mbps.log
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