Re: [tlug] Disk I/O bottleneck: how to solve?

[David Beutel <david_beutel2@example.com>]

I'm sure it's possible to tell Linux to use bigger
disk buffers.  Sorry, but I don't know how off-hand;
it's probably a kernel configuration parameter, but I
don't know whether you'll need to rebuild your kernal
or just pass a parameter at boot time.  Or maybe it's
all a module now?

By the way, if you didn't have 200M of free RAM, the
Disk I/O bottleneck might have been coming from
thrashing (i.e., swapping processes to disk too often,
because of lack of RAM).

Also, a bigger disk buffer won't help much for
high-reliability processes that want the kernel to
guarantee that it's actually finished writing to the
disk, e.g., a database server committing a
transaction.

11011011

--- Jean-Christian Imbeault
<jean_christian@example.com> wrote:
> One of my machines has been showing poor performance
> lately and I think I've 
> pinned the problem down to a hard disk I/O
> bottleneck.
> 
> The hard drive is already pretty fast (ATA-100 7,200
> rpm). I only have two 
> drives bays and both are in use so trying to speed
> things with RAID are not 
> an option.
> 
> I could upgrade the hardware but I don't think there
> are any faster IDE 
> drives (I heard that ATA-133 is really only about 5%
> faster that ATA-100). I 
> *could* go SCSI but since it is a much more
> expensive option it would need 
> to be a big imporvement in speed.
> 
> I was wondering if the were any software options? My
> machine has a lot of 
> free RAM and I was wondering if there was any way to
> make the kernel use 
> more RAM as a disk buffer? My machine always has at
> last 200M of free RAM 
> (total of 512M) so using that as a disk buffer could
> really speed things up.
> 
> Is it possible?
> 
> If there are other solutions I have overlooked
> please let me know ofoucrse 
> ;)
> 
> Jc
> 
> 
> 
>
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