1. Make your servers work for you, not the other way round.
2. Do it the same, over and over and over again
3. Backups are sacred! If you do not know if your backups are current, then test them by restoring the data and comparing.
4. Do not make many, tiny partitions, make a smaller number of larger partitions, instead.
5. Why change the system default when you don’t have to?
6. Think now so you don’t have to later (at 4am).
7. If you have to do it more than once, automate it. If you cannot automate it, document it.
8. Personality is for people, not for computers.
9. “Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.” - Brian W. Kernighan
10. If you do not know what a machine will do when it is rebooted, then it is not production ready.
11. Unless you write an essay on why you need to do something “special” use the tools, procedures, techniques and resources the OS provided for you.
12. Remember the Mack Truck Scenario: If no one will be able to figure this out if you get hit by a Mack truck, then you’re doing something wrong.
13. Revision Control! Comment!
14. Log and rotate logs. Log remotely for best effect.
15. Simplicity is its own reward.
16. If you haven’t thought of at least one potential negative outcome of hitting enter at the end of the command you just typed; then you don’t understand the command well enough to use it on a production system.
17. Use a unique marker for names of packages that are locally developed. $domainname perhaps?
18. If you cannot enumerate every port that should be listening on a given machine; then it is not production ready.
19. If the host firewalling allows access to more ports than ABSOLUTELY necessary; then the host is not production ready.
20. If it seems like someone else would have encountered this problem before, they probably have. We do not live in a vacuum. Google for the answer.
21. DOCUMENT!

Os-Specific:

Solaris

1. Never ever make /tmp its own partition.
   What??? Use tmpfs as it was intended! If you are worried about apps filling /tmp and starving memory or vice versa use appropriate unlimited controls! That’s what they are there for.
2. Nothing belongs in /etc/rcN.d except links to scripts in /etc/init.d

Linux

1. If you’re installing a binary and it’s not installed using the system packaging mechanism, then you are doing something wrong.
2. Linux is not like Solaris, do not treat it as such.

Finally, server consolidation at Webvisions data centre is 99.9% completed. It’s been going on for the past 2 months, from setting up of the 4 new servers inside office to transporting them to data centre for in processing to mounting them 1 by 1 onto the server racks, shifting and swapping positions of the servers, rearranging the network cables, testing of the applications, network connections, 2 Monday mornings (2am onwards) of power source transfers, coordinating with clients and programmers for migration work of IMS, migration of the application and MX servers over different occasions due to client’s EDM blasts schedule and programmer’s super tight work schedule till now, ALL DONE! The last step is to go down to data centre and outprocess the old servers and bring them back to office!