Hi,
Ususally it happens some times,
Your checks should be,
1]CPU :
Check out the top processes which are using most of the CPU.
#UNIX95= ps -ef -o pid,ruser,pcpu,args|tr -d "%" |awk '{if($4>=90) print $0}'
Also check
#ps -ef |grep -i NO (For oracle process)
Well if you find almost all processes (oracle)are in sleep state since long time,then u can take the decisions to kill the same with proper approvals,
But after looking at vmstat output,cpu is idle and there is hardly utilisation.
2]Memory :
It is most important parameter to check if you are getting very slow response.
in vmstat output, i am looking lots of page out, it means u are going short of memory,and swap utilisation is more.check,
#swapinfo -tam,
Action :
If you see more swap utilisation,then,
run below command,
#ipcs -mob
ex.
#ipcs -mob
IPC status from /dev/kmem as of Tue Aug 25 13:34:26 2009
T ID KEY MODE OWNER GROUP NATTCH SEGSZ
Shared Memory:
m 0 0x411c0189 --rw-rw-rw- root root 0 348
m 1 0x4e0c0002 --rw-rw-rw- root root 2 61760
m 2 0x41201f8a --rw-rw-rw- root root 1 8192
m 3 0x00a5c581 --rw------- sfmdb users 4 10469376
m 32772 0x06347849 --rw-rw-rw- root root 2 65544
m 65541 0x0c6629c9 --rw-r----- root root 2 17868736
m 163846 0x491823a2 --rw-r--r-- root root 0 22908
If you see 7th Column (NATTCH )any process is having 0 value, that means thease processes are completed and still they didn't release the memory segment
You can release thorough
#ipcrm -m (Be careful while running this command)
3]Disk utlisation :
#Using iostat command,check any perticular disk is showing any abnormal behavior,
4]Network
On critical server,usually export,back thease activities should do when there will be less load on the server.these can be depend on LAN speed.
Check thease statictics as well,
Hope above points may help u in some manner.
Rgds
Yogesh
