Since upgrading my user's crontab has been wiped out.This is not the first time this has happened this year and it's a pain restoring it each time.#· # For example, you can run a backup of all your user accounts # at 5 a.m every week with: # 0 5 * * 1 tar -zcf /var/backups//home/ #· # For more information see the manual pages of crontab(5) and cron(8) #· # m h dom mon dow command These lines all start with a # because they are comments; they are ignored by cron, and are just there for you to read. The information you must include is (in order of appearance): A "number" is an integer, for example 5.A "list of numbers" is a set of integers separated by commas, for example 15,30,45, which would represent just those three numbers.The crontab is a list of commands that you want to run on a regular schedule, and also the name of the command used to manage that list.crontab stands for "cron table," because it uses the job scheduler cron to execute tasks; cron itself is named after "chronos," the Greek word for time.It may even be more preferable to use per-user crontabs and some other workaround to whatever this "unified crontab" is intended to overcome... Another suggestion, if you're dead set on sharing a crontab - use a version control system (git, cvs, svn) to host the necessary file, and have the server check it out to the necessary location when its checked in.
The first command will determine if any outstanding patches are available, and if so, will list the files that will be modifed if the patches are applied. If the update applies any kernel patches, the system will need a reboot in order to boot into the patched kernel. will attempt to download all files required for the upgrade.If you’ve never sent a command typically means "re-read your configuration files, something just changed".I used to use it all the time with the cron and inetd daemons, issuing that command whenever I changed their configuration files.of the crontab with a previously saved version to at least be able to see what has been changed, but I thought that perhaps there is a standard solution for this. It might seem overly complicated but there is nothing too complicated with what I described if you break it up into small chunks.Another approach would be to use a tool/script such as Multi Cron.