Re: Linux and SSD and how to decrease io delay : question, please

[Bill Davidsen <davidsen@tmr.com>]

 > DanielMariella Petrini wrote:
> Hi,
>
> I have run a benchmark using the latest Linux kernel
> and having
> still the elevator set to noop (for each hard drive)
> and vm.dirty_expire_centisecs = 6000
>
> The system has 24GB of RAM, 2 SSD Mtron drives on a
> RAID controller.
> The databases are spread across two ext3 filesystems
> mounted on the SSD drives (one filesystem maps to one
> SSD drive and the other one to the other SSD drive.
> Each drive is seen as a single volume).
> The system has 2 cpus with 2 cores each.
>
>   
Have you mounted those filesystem with the "noatime" option? If you 
don't do that you risk causing a *lot* of unwanted seek and write 
activity to the journal.
> Before starting each benchmark the system has
> approximately 16GB of RAM already cached (so that most
> of the file reads are reduced)
>   

-- 
Bill Davidsen <davidsen@tmr.com>
  "Woe unto the statesman who makes war without a reason that will still
  be valid when the war is over..." Otto von Bismark