Re: [patch 2/3 v3] raid1: read balance chooses idlest disk for SSD

[Roberto Spadim <roberto@xxxxxxxxxxxxx>]

for SSD without inteligent parts (cache and queue) i think this could
works nice... (at least in theory)
for USB sticks and microsd cards may work too...


2012/7/2 Shaohua Li <shli@xxxxxxxxxx>:
> On Sun, Jul 01, 2012 at 11:13:42PM -0300, Roberto Spadim wrote:
>> nice =) very very nice =)
>> maybe to get better than this... select the disk with min(pending time)
>>
>> time could be estimated with something like:
>> (distance * time/distance unit) + (blocks to read/write * time to
>> read/write 1 block) + (non sequencial penalty time)
>
> I didn't think there is way to measure request time. Disks support NCQ, they
> can dispatch several requests at one time and finish them almost at the same
> time. I used to measure this time (to make CFQ ioscheduler self tune), but
> failed.
>
> Thanks,
> Shaohua
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



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