Re: [PERFORM] linux distro for better pg performance

[Gavin M. Roy]

I am searching for best pg distro to run pg (7.4.1).
 

This is generally based upon opinion.  Honestly though, your kernel 
version is more important for performance than the distro.  Personally I 
use gentoo, love gentoo, and would recommend very few other distros 
(Slackware) for servers.  RedHat and others seem to include 
kitchensinkd, when it's not needed.

At the moment I am using RedHat AS 3.0, but I think it have some
performance problems (I am not sure).
My configuration:
P4 2.8 GHz
1 GB RAM
120 GB IDE 7200 disk.
 

Your IDE drive is the biggest hardward bottleneck here.  RPM's and bus 
transfers are slower than SCSI or SATA.

Kernel version 2.4.21-4.EL (it is the installation vesrion for rh 3.0) .
 

Jump to 2.6, it's much better for performance related issues, in my 
experience.

My problems:

If I run some query with many reads, I see a massive disk transfer :
procs                      memory      swap          io
system         cpu
r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy
id wa
0  0      0 261724   3252 670748    0    0     0     4  105    19  0  0
100  0
0  0      0 261724   3252 670748    0    0     0     0  101    11  0  0
100  0
0  0      0 261724   3260 670748    0    0     0     4  104    19  0  0
100  0
0  1      0 259684   3268 674112    0    0   964     7  131    57  0  0
95  4
1  0      0 119408   3288 808540    0    0 27960     0  572   630 13 14
24 49
1  1      0  15896   3292 914436    0    0  7984 44744  531   275 11 18
24 47
0  2      0  16292   3296 924996    0    0  4145  6413  384   176  2
5  0 92
0  1      0  19928   3316 928844    0    0 11805 13335  497   388  5
9  5 81
0  3      0  19124   3296 924452    0    0  3153 19164  287   295  5 11
16 68
0  1      0  15956   3304 932984    0    0   536  6812  366   123  4
6  3 87
0  2      0  24956   3300 921416    0    0  1931 22936
And if I run top, I see a big iowait % (some times 70-80) and very low
user % (10-15).
 

again, this is your harddrive, and the kernel can play into that.

I readet many docs about this problem, but do not find any solution.

My question:

If some one is using RH 3.0, pls post some result or suggestions for it
performance with pg .
What is the best linux distro for pg?
 

There's no best, just personal preference.

Can I get better performance by using 15K SCSI disk ?
 

Absolutely

Or it will be better to have more RAM (2 or 3 GB) ?
 

Better to have a fast drive, but more ram can be helpful.

regards,
ivan.
 

HTH,

Gavin

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