All about the system administration and application development behind a local linux-based company
I told myself when I started this blog that I was going to avoid simple howto posts and focus on system administration concepts. However, I’m going to break that rule today. I was looing through my referrer log files, and noticing that I get a lot of search queries for “How to…” or “how doI…” So, I dug up my access logs, fired up egrep, and made myself a list of search referrals with “how” in the string. Today I’m going to give in to the masses and attempt to answer some of them :
Clusterssh and shmux do this, as mentioned in a previous post. For a more scalable system, also have a look at puppet.
run “yum update” to update all of your software packages. Be sure to restart after a kernel update.
Tripwire is a commercial product, so RTFM or bug support. Also see aide for a free version with similar design goals.
Do you really want to do this? Might ssh/scp/rsync over ssh be a better option? The only possible reason is for speed in an isolated network, where every machine on the network is trusted.
Install the packages rsh-server and xinetd. edit /etc/xinetd.d/rsh and change disable = yes to disable = no. Add .rhosts files as needed. To enable rlogin, do the same for /etc/xinetd.d/rlogin
It isn’t installed by default. If it is installed, edit /etc/xinetd.d/rsh, /etc/xinetd.d/rlogin, and /etc/xinetd.d/rcp and add “disable = yes” to all of them. Or, just remove the whole package with “yum erase rsh”
Run yum check-update , intuitively enough
If you must, install the telnet-server package and enable the service in /etc/xinetd.d/telnet
Thanks to Andrew for the suggestion to add a plug for ssh here.
I assume you mean how to disable root ssh logins. open /etc/ssh/sshd_config and add a line “PermitRootLogin no” Addition: Also, set more restrictive permissions to /bin/su so that people can’t log into ssh as a normal user and su to root.
Since the old kernel should still be installed, simply edit /etc/grub.conf and change default=0 into default=1 Be sure to change it back when you get the kernel working, or you will perpetually be running one kernel behind current
See my post on getting email notifications which I think is a better strategy. If you really must do automatic updates, create a daily crontab that runs yum -y update.
pidgin.
March 20th, 2008 at 8:05 am
If you’re going to tell people not to use telnet (a good thing) then you should at least point them to the alternative (SSH/OpenSSH).
Just a thought.
- A.
Response: Note taken. –Erek