Killer SCSI 1 TB fileserver (Part 2)

[Bill Broadley]

A couple of you asked me to keep you up to date with my fileserver
experience. 

I built a new fileserver:	
	6 GB ram
	Dual p4 xeon (with hyperthreading, yes linux sees 4 cpu's)
	Intel e7500 chipset based board
	AIC-7899A * 2 (U160) channels on the motherboard 
	1 TB disk (3 channels of U160, 5 73 GB disk per channel).

I managed to almost TRIPLE my read performance of the old config, 300 MB/sec
sustained for over 12 GB!  I don't think the cache helped much if at
all considering I never saw the buffers/cache exceed 150 MB or so.

5 disk raid-0:
2xP4,12G,,,88470,88,44419,34,,,144447,38,746.6,2,16,1863,98,+++++,+++,+++++,+++,1936,99,+++++,+++,5191,99
Version  @version@      ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
2xP4            12G           88470  88 44419  34           144447  38 746.6   2                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min        /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
2xP4             16  1863  98 +++++ +++ +++++ +++  1936  99 +++++ +++  5191  99

10 disk raid-0:
2xP4,12G,,,96023,99,81299,73,,,311175,89,944.8,4,16,1883,99,+++++,+++,32624,99,1916,99,+++++,+++,5088,100
             total       used       free     shared    buffers     cached
Mem:       6199836     231724    5968112          0      30996      40908
-/+ buffers/cache:     159820    6040016
Swap:      6291408          0    6291408
Version  @version@      ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
2xP4            12G           96023  99 81299  73           311175  89 944.8   4                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min        /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
2xP4             16  1883  99 +++++ +++ 32624  99  1916  99 +++++ +++  5088 100

Immediately after the run:
             total       used       free     shared    buffers     cached
Mem:       6199836     204124    5995712          0      29240      35904
-/+ buffers/cache:     138980    6060856
Swap:      6291408          0    6291408

Any suggestions on how to improve writespeed?  Even with double the number
of disks I only saw minimal improvement (86.4 MB/sec to 93.77 MB/sec).

Oh the partition was formated as Ext3.  Has anyone else managed significantly
higher write bandwidth with hardware or software raid?

-- 
Bill Broadley
Mathematics/Institute of Theoretical Dynamics
UC Davis