Archive
Posts from 2009
Deploying Highly Available Virtual Interfaces With Keepalived
I recently played around with keepalived, and documented my experiences in an article titled Deploying Highly Available Virtual Interfaces With Keepalived. If you are interested in deploying highly available Linux routers, or just looking to failover IP addresses between servers, you may find the article useful.
$ read more →Triple parity RAIDZ (RAIDZ3) support in ZFS
I just saw the following putback notice come over the wire: This is pretty sweet, and with the introduction of 2TB+ drives, using multiple parity drives will become essential to ensuring that your data is safe when a drive failures occur.
$ read more →Creating home directories on Linux hosts with pam_mkhomedir
I have been converting a number of hosts to LDAP authentication. I'm currently creating user home directories on each server, which has a number of pros and cons. One of the cons is that a newly provisioned user won't have a home directory, all will be assigned "/" as their home directory when they login. This is less than ideal, since most users will need a place to modify files and customize their environment…
$ read more →Figuring out when files change on Centos and Fedora hosts
Vijay Avarachen posted a great tip on Linux Journal's website. In the article Vijay posted, he shows how to use rpm along with the verify option to list files that have changed: Yum has a similar capability, which can be accessed through yum-plugin-verify plugin. This plugin adds the verify-all and verify-rpm options, which can be used to list files that have changed (you will need to edit /etc/yum/pluginconf.d/verify.conf to make the plugin as useful as the rpm --verify option). Good stuff!
$ read more →Installing a tftp server on CentOS and Fedora Linux servers
While upgrading the firmware on several network devices this past weekend, I needed to bring up a tftp server so the clients could retrieve the firmware image. I had a Fedora host readily available, so getting tftp up and working was super easy. Before configuring the server, I ran yum to install the tftp-server package: Once the package was installed, I set "disable" to no in /etc/xinetd.d/tftp (I also disabled the server as soon as I was done using it): After the server was configured, I restarted xinetd and everything worked like a champ. If you encounter any issues tftp'ing files, there are a couple of things you can do to troubleshoot the source of the problem: Add one or more "-v" (verbose output) directives to the /etc/xinetd.d/tftp "server_args" line Start the tftp client by hand, and set the "verbose" and "trace" options Fire up tethereal to decode the TFTP requests and responses While tftp is completely insecure, it's still one of those protocols that we have to live with.
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