Most newbies ponder the question, “what version of redhat am I actually running?”.
# uname -a
will give you a load of useful information; but not, say, “CentOS 4.3″.
It is rather simple, simply type the following command (without #):
# tail /etc/redhat-release
This will output something like: CentOS release 4.4 (Final)
And you’re good to go!
A while ago there was an update to the YUM package management system for CentOS. It’s quick and painless and if youre NOT behind a proxy it’s actually recommended by the devs as well.
To install it simply type:
# yum install yum-plugin-fastestmirror
And you’re done!
Now everytime you run a yum update yum will automatically select the fastest mirror for your server and download the files.
A note though: If you find that it fails frequently after a popular security patch or update has been released, you may need to type yum update several times before it actually gets through. It hasn’t happened me to much though.
I have a box that is supposed to send out email. I noticed that none of these emails were actually getting sent!
I looked through my /var/log/maillog log and found some lines that looked like this:
Oct 11 15:39:33 server sendmail[12789]: k9BKdX65012789: from=root, size=802, class=0, nrcpts=1, msgid=, relay=root@localhost
Oct 11 15:39:33 server sendmail[12789]: k9BKdX65012789: to=admin@somedomain.com, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30802, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: Connection refused by [127.0.0.1]
So I figured that the localhost must not be properly configured in my /etc/hosts file, and lo and behold, it wasn’t!
I changed the line in /etc/hosts to read: Read the rest of this entry »