Topic: What is this?

[pippin]

Existing lock /var/run/yum.pid: another copy is running. Aborting.

Everytime i do a yum update in putty

[william_syd]

Existing lock /var/run/yum.pid: another copy is running. Aborting.

Everytime i do a yum update in putty

If this is just after rebooting then the server-manager may still be checking what updates are available.

[natdata]

it could be that you had some kind of power or system failure while yum was running. This could leave the lock file in place even though yum isnt still running. if the problem persists try deleting that yum.pid file.

[byte]

Why delete it? why not wait till the yum has finished doing what it's doing, once it has you can run yum again