Hi,
just want to know while working with RedHat,CentOS and other Linux distro what are the general issues a Linux system Administrator faces on day to day basis?

Thanks & Regards

It's a huge list, and will vary by site. Basic job? Keep server(s) up, running, and available, 24/7/365, no excuses. Details include:

• Updating software
• Updating/patching the OS
• Network configuration
• Hardware configuration
• Rack maintenance
• Systems monitoring
• Backups/restores

Those should keep you quite busy, and again, things will vary by site. Some shops have an enterprise backup system (Tivoli, Netbackup, etc), and will have backup administrators that perform that whole task. Or, you may have to just load an agent..who knows? Software updates?? Sometimes the server-users will do it, or you may have to. Same with networking...the telcom/network folks may do it, and hand you a wire and address, or you may have to dive in and do it yourself.

My bigest job is fixing stuff that some user managed to FUBAR.

On top of what TBone said, we have machines that we have to test the updates BEFORE we apply them. This is done by having a clone of the working machine and the updates are applied to it first to check for problems(usually for at least two weeks). While issues with updates are fairly rare, one only has to be burned once before one becomes extremely careful.