[CentOS] Adding RAM

[Matt]

>> Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s
>> avgrq-sz avgqu-sz   await  svctm  %util
>> sda          0.38 176.63 70.32 78.26  813.46 2044.82   406.73  1022.41
>>   19.24     0.40   19.17   4.04  60.07
>> sda1         0.00   0.00  0.00  0.00    0.00    0.00     0.00     0.00
>>    5.28     0.00   23.61  19.33   0.00
>> sda2         0.38 176.63 70.32 78.26  813.45 2044.82   406.73  1022.41
>>   19.24     0.40   19.17   4.04  60.07
>> dm-0         0.00   0.00 70.71 255.60  813.45 2044.82   406.73
>> 1022.41     8.76     2.90    8.87   1.84  60.10
>> dm-1         0.00   0.00  0.00  0.00    0.00    0.00     0.00     0.00
>>    8.00     0.00   64.20  11.38   0.00
>
> Try setting the scheduler to 'deadline' and see if the queue sizes
> shrink.

I have googled this and having a bit of trouble figuring how to change
it under CentOS 4.

http://www.wlug.org.nz/LinuxIoScheduler

Does not seem to work on CentOS 4.

> No raid1? Besides adding redundancy, it can help with read
> performance. I would probably put the mail on a raid 10 though if I
> had 4 disks to do so.

I plan on moving to faster disks and RAID 1 down the road.  Just has
not happened yet.

Matt