trying to get a good understanding as to how different people manage their linux servers, particularly in a multiple server environment. what tools do you use to install/upgrade your software? yum/apt-get/etc...?? do you use a control panel (exsim/plesk/cpanel)???
also, when you're loading/upgrading software, do you do any kind of rigorous testing to determine if the app really runs with the other apps on the system?
also, given your environment, what's the biggest pain/issue you deal with?
we've got a handful of systems that we're dealing with, and sometimes it gets to be a pain, especially when we're not sure if we're screwing something up!
we use hsphere for our servers. It is a multiserver solution. I don't take care of the server updates and all myself, we have sys administrator for that, but I believe he is using yum. Hsphere takes away alot of the trouble when dealing with a multiserver environment.
We manage a large number of H-Sphere clusters for H-Sphere hosting providers.
Some of our clients are running RedHat 7.2, RedHat 7.3, and CentOS.
For those customers, we use yum.
Some are running RedHat Enterprise ES 3; and for that we use the RedHat Update Network (RHN) along with the "up2date" utility.
Some are running FreeBSD, and for that we use ports.
We try to use roll back features whenever possible in terms of operating system updates.
Since we manage a large number of clusters, we take the approach of first testing updates on our own lab, then our own servers, then for those clients that want cutting edge; and after everything looks good, for our other clients.
Over the past nine of the ten years we have been in business (9 being Net oriented), this has worked out rather well to make sure there are no problems.
We also encourage backups as well.
Also, when dealing with H-Sphere, we have a procedure in place so we, ourselves, are backing up key files prior to updates.
I guess the biggest thing to share is to have a written procedure you can follow on a consistent basis.
I also recommend keeping a software inventory so you know what applicaitons, versions, etc. are on each server.