Unix Health Check


Note Many of these procedures can be scripted.

1.  Check for problem conditions
system logs error/warning

HPUX:  
grep -i  -e "EMS" -e "error" -e "warning" -e "excessive" /var/adm/syslog/syslog.log | more
tail /etc/shutdownlog

hardware problems

HPUX:
ioscan -fnC disk | more
ioscan -fnC fc | more
ioscan -fnC processor | more
ioscan -fnC ba | more
ioscan -fnC memory

filesystems full

HPUX:
bdf | more

AIX|SUN|LINUX
df|more


2.  Overview of the system
top/topas
glance (if HPUX)

Processor Utilization
Disk Utilization
Memory Utilization
Paging/Swapping
Busiest Processes



3.  Memory
RAM
Swapping/Paging

swapinfo

vmstat  (avm - active virtual memory pages, pi - pages swapped in, po - pages swapped out)

sar -g
sar -w ??
ipcs

Are the swap disks > 50% busy?

4.  Processor Bottleneck

% utilization
% system time vs %user time
uptime
sar -q  (runq-sz  run queue, swpq-sz  swap queue)
sar -u  (%usr, %sys, %wio - wait i/o)
On Sun
iostat -xc
Don't collect more than 100 samples
Strip out idle disks
Set an appropriate interval
For 24 hours use 15 mins
For 10 mins use 10 secs

5.  Disk Bottleneck

In General

Check for adequate free space
Check for high utilization
sar -d   (%busy and avque)
iostat (bps - kb per sec)
On Sun

iostat -xn 30
Look for disks > 5% busy and average response times > 30 ms  (svc_t)



6.  Processes
Busiest Processes  ps -ef | sed 1d | sort -rn +6|head
Zombies  ps -ef|grep -i defun


sar -w  (swpins, swpots)
vmstat (procs - b  => blocked)

7.  Network
Utilization
Packet rate on each interface
Errors

netstat -s | more

nettune/ndd
nfsstat

netstat -i
nfsstat
netstat -s