Please help me to tune this server. It is hosting server most of the website using Vbulletin. we have arround 30 website hosted in this server. Some times websites getting "Network Error " and load also increasing..

Cpanel
--------------------------
Apache =1
php 4.4.7
---------------------------
Timeout 90
KeepAlive On
MaxKeepAliveRequests 130
KeepAliveTimeout 3
MinSpareServers 20
MaxSpareServers 40
MaxClients 250
StartServers 15
MaxRequestsPerChild 500

[root@hoi1 src]# ps aux | grep -c http
56


[root@hoi1 src]# free -m
total used free shared buffers cached
Mem: 2026 1986 39 0 48 1148
-/+ buffers/cache: 790 1236
Swap: 1992 158 1833

--------------------
MYSQL

4.1.22-standard

my.cnf

[mysqld]
skip-locking
skip-innodb
max_connections = 750
key_buffer = 196M
myisam_sort_buffer_size = 16M
join_buffer_size = 2M
read_buffer_size = 2M
sort_buffer_size = 2M
read_rnd_buffer_size = 4M
table_cache = 1500
thread_cache_size = 64
interactive_timeout = 60
wait_timeout = 60
connect_timeout = 10
tmp_table_size = 32M
max_allowed_packet = 16M
max_connect_errors = 10
thread_concurrency= 4
query_cache_limit = 1M
query_cache_size = 64M
query_cache_type = 1

[mysqld_safe]
err-log=/var/log/mysqld.log
open_files_limit = 8192

[mysqldump]
quick
max_allowed_packet = 16M

[myisamchk]
key_buffer = 64M
sort_buffer = 64M
read_buffer = 16M
write_buffer = 16M


TOP
_____

top - 13:24:38 up 5 days, 18:52, 9 users, load average: 0.14, 0.17, 0.17
Tasks: 184 total, 1 running, 183 sleeping, 0 stopped, 0 zombie
Cpu(s): 8.5% us, 1.7% sy, 0.8% ni, 71.1% id, 17.7% wa, 0.1% hi, 0.0% si
Mem: 2074696k total, 2024172k used, 50524k free, 52084k buffers
Swap: 2040212k total, 162228k used, 1877984k free, 1193844k cached

PID USER PR NI %CPU TIME+ %MEM VIRT RES SHR S COMMAND
1 root 16 0 0 0:10.34 0.0 2532 468 436 S init
2 root RT 0 0 0:00.35 0.0 0 0 0 S migration/0
3 root 34 19 0 0:00.02 0.0 0 0 0 S ksoftirqd/0
4 root RT 0 0 0:00.28 0.0 0 0 0 S migration/1
5 root 34 19 0 0:00.02 0.0 0 0 0 S ksoftirqd/1
6 root 5 -10 0 0:00.17 0.0 0 0 0 S events/0
7 root 5 -10 0 0:00.17 0.0 0 0 0 S events/1
8 root 9 -10 0 0:00.00 0.0 0 0 0 S khelper
9 root 15 -10 0 0:00.00 0.0 0 0 0 S kacpid
34 root 5 -10 0 0:00.00 0.0 0 0 0 S kblockd/0
35 root 5 -10 0 0:00.00 0.0 0 0 0 S kblockd/1
36 root 15 0 0 0:00.00 0.0 0 0 0 S khubd
55 root 15 0 0 11:15.83 0.0 0 0 0 S kswapd0
56 root 14 -10 0 0:00.00 0.0 0 0 0 S aio/0
57 root 10 -10 0 0:00.00 0.0 0 0 0 S aio/1
201 root 25 0 0 0:00.00 0.0 0 0 0 S kseriod
430 root 5 -10 0 0:00.00 0.0 0 0 0 S ata/0
431 root 5 -10 0 0:00.00 0.0 0 0 0 S ata/1
432 root 8 -10 0 0:00.00 0.0 0 0 0 S ata_aux
436 root 15 0 0 0:00.00 0.0 0 0 0 S scsi_eh_0
437 root 15 0 0 0:00.00 0.0 0 0 0 S scsi_eh_1
458 root 15 0 0 0:03.85 0.0 0 0 0 S kjournald
516 nobody 16 0 0 0:06.72 0.6 24692 12m 2420 S httpd
517 nobody 15 0 0 0:05.35 0.6 24732 12m 2420 S httpd
518 nobody 16 0 0 0:04.07 0.6 24400 12m 2104 S httpd
637 root 16 0 0 0:00.49 0.1 6668 2676 2144 S authProg
665 nobody 16 0 0 0:06.59 0.6 24424 12m 2468 S httpd
680 nobody 16 0 0 0:05.22 0.7 25700 13m 2420 S httpd
683 nobody 16 0 0 0:06.15 0.7 25128 13m 2468 S httpd
684 nobody 15 0 0 0:05.92 0.7 26060 14m 2824 S httpd
997 nobody 15 0 0 0:03.18 0.5 22244 10m 2420 S httpd
998 nobody 16 0 0 0:04.75 0.5 22520 10m 2384 S httpd
1031 nobody 15 0 0 0:02.16 0.5 22296 10m 2084 S httpd
1039 root 6 -10 0 0:00.00 0.0 0 0 0 S kauditd
1301 nobody 15 0 0 0:01.30 0.5 22184 10m 2112 S httpd
1723 root 6 -10 0 0:00.00 0.0 3408 348 344 S udevd

---------------
CPU
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel® Xeon® CPU 3060 @ 2.40GHz
stepping : 6
cpu MHz : 2400.135
cache size : 4096 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc pni monitor ds_cpl est tm2 xtpr
bogomips : 4802.98

processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel® Xeon® CPU 3060 @ 2.40GHz
stepping : 6
cpu MHz : 2400.135
cache size : 4096 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc pni monitor ds_cpl est tm2 xtpr
bogomips : 4800.22

Please post stats from a busy time. It's difficult to suggest any changes when the load is so low.

You may need to disable mod_evasive if you have installed it.