Edit: It seems to still be an issue where the people that built machines are not necessarily the ones that manage and maintain machines as time goes on.
Originally posted April 8, 2008 on AIXchange
You need to log-on to a machine that you’ve never seen before. There’s no documentation. The administrator who built and ran the machine is no longer with the business and left nothing behind, so nobody has any idea how it was put together. The machine just sits in a corner and runs.
So what are some of the first commands you use to get more information?
To answer this question, you should ask several more. What are you trying to understand? Do you want to know how the disks are laid out? Do you want to know how the application starts? Do you want to know what is running in cron or what applications are running on it now?
This is by no means comprehensive, but a few things that I like to check on a machine would be found in the output from these commands:
oslevel –s
instfix –i | grep SP
hostname
lsdev –Cc adapter
netstat –rn
netstat –in
cat /etc/hosts
cat /etc/resolv.conf
lslpp –l
rpm -a
lscfg
prtconf
lsmcode
lssrc -a
lspv
lsvg
df
lsfs
lsps -a
uname -L
errpt –a
crontab –l
I’ve left a few things off this list. What other commands would you add?
Do you have scripts and tools that you like to load and run on a “foreign” machine? Do you keep copies of how the machine looks so that you can easily compare today’s output to last week’s? Do you have run books or other documentation–not to mention any necessary backups–to use if a machine rebuild is needed?
Although in many cases the people who build the machines are also the ones who run them day to day, it’s not always the case. Sometimes, due to the size and complexity of the environment or the simple fact that people do switch jobs in IT, the guy who loaded and understands the machine may not be available to do work on it now.
That leaves it up to us. We need to be able to log-on to any machine, learn about the environment and then do what needs to be done. It starts with knowing which commands to run.