What's the biggest time saver you've implemented? [closed]

Which changes that you have implemented did have the biggest impact on saving time in you daily sysadmin workload? What are your tricks to work more efficient and get more things done or work less for the same results?

I'm thinking about automation, changes in workflow/processes, new tools, stop doing some things altogether, outsourcing, better delegation, changing software/hardware, reducing bureaucracy, etc.

monitoring+alerting - which is great safety net. just as developers write unit tests to make sure things don't get messed up when they update code, i rely on monitoring as additional safety net just in case i screw something up [ that is disconnect a server, deny production traffic on firewall etc ]. it gives a peace of mind - if things break i will know before customers call.

For me, it has been centralized authentication.

I got to the point that I was administering 40 or so Slackware machines, and each one had local authentication PLUS local Samba authentication. I also had a VPN solution where each account needed to be setup, plus an internal jabber server and an internal email server. Everything had its own account. MAC (Moves, Adds, Changes) were insane.

So I switched from Slackware to CentOS, created an Active Directory infrastructure, and used Likewise Open to authenticate all of my Linux machines against AD. It probably saved me 20 hours a month without joking even a little.

Now, I've got everything authenticated through AD that I can, and it works tremendously. I can't recommend centralized authentication enough if you're still doing things the bad old way.

I agree with the obvious choices here; Automation and central authentication. However, it appears that I have to be the guy to mention documentation.

By documenting as many problems, workflows, installations and guides as possible people were able to work through some of their issues without the need to get our department on it.

Another great time saver is issue tracking.

Being able to prioritize tasks, assign them to team members and getting rid of all the clutter of people sending in requests by email, msn or simply coming to the office. This also helps our good friends, the managers with seeing how efficient you are (if you want).

Then of course, the icing on the cake would be my 'RTFM' (Read the Fine Manual) mug that gets raised a lot.