4. Redhat Linux : RHCE 6
RPM (Redhat Packet Management)
------------------------------
* do not resolve dependencies
* installation package should be in the pwd
YUM (Yellowdog Update Management)
---------------------------------
* resolve dependencies itself
* install from the network
* configure yum:
Install vsftp and createrepo
Copy packages to /var/ftp/pub/anyname(if you want to access from other clients)
Run createrepo command 'createrepo /var/ftp/pub/anyname'
Create /etc/yum.repos.d/packages.repo and include:
[server]
name=packages.repo
baseurl=ftp://192.168.x.x/pub/anyname
enabled=1
gpgcheck=0
Restart vsftp using 'service vsftp restart'
vsftpd:
------
* very secure ftp
* used to network install using yum
Job Scheduling
--------------
3 Types:
-------
* cron : periodically
* anacron : different periods
* at : one time
fields in crontab:
-----------------
minutes hours days of month month Days of week
eg: */1 * * * * echo "Hello" > /dev/pts/4
eg: 06 15 26 * * sh script.sh > /root/cron_out
* all the users can schedule the crone and at jobs by default
* to deny permission for any user add user in /etc/cron.deny
* to deny permission for any user add user in /etc/at.deny
Updating Kernel:
---------------
* rpm -ivh kernel.rpm
* vim /etc/grub.conf and edit as
default=1
* yum update
/*
Commands for the day:
--------------------
* rpm -ivh packageName.version.release.arch.rpm : installs the package
* rpm -q package : queries the package
* rpm -qd package : document of the package
* rpm -e package : removes the package
* yum install package : to install packages
* yum remove package : removes the package
* yum info package : gives info about the package
* yum update : update the system
* crontab -e : add cron jobs
* crontab -e -u username : add cron jobs for any user
* crontab -l : list all cron jobs
* crontab -r : remove cron jobs
* at now : schedule at current time
* at 23:59 : schedule at user defined time
* at -l : list all scheduled jobs
* at -r : remove all scheduled 'at' jobs
* createrepo /var/ftp/pub/anyname : create local installation repository
* service vsftp restart : restart vsftp service
*
