We started using 389 LDAP (aka Fedora Directory Server) for user and group management in our research computing environment. Instead of managing users, groups and passwords on each and every machine, we just put them in LDAP and have all the machines authenticate users centrally; it’s not rocket science (people have been doing centralized LDAP […]
I’ve been using Con Kolivas’ linux-ck patch set for a few years now. If you’ve ever asked yourself “It’s 2013, why does my music playback skip when I do too many things on my computer?!” then you probably need to look if your distro has a ck-patched kernel. A large part of the ck patch […]
I recently re-worked our SLURM configuration to extrapolate the number of logical CPUs based on Sockets, Cores, and Threads. Therefore, a machine with four eight-core Xeons and HyperThreading would have 64 logical CPUs available to SLURM; 4 * 8 * 2 = 64. I thought I was being clever, but it turned out to bite […]
If you’ve got more than two or three CentOS machines on your network, it’s really a waste of time and bandwidth for each machine to download the same updates as the previous/next machine. Or, sometimes you tell your users “I just need 5 minutes to run some updates and reboot” and it ends up being […]
I mount all ext4 partitions on my solid-state disks with the discard option; this tells the filesystem to use SSD-specific low-level TRIM operations instead of normal erases (which are essentially just block re-writes). As I use my SSDs quite heavily, I like to perform batch discards every so often as well. Here’s a systemd service […]