Storage caching options in Linux 3.9 kernel

dm-cache is (albeit still classified “experimental”) is in the just released Linux 3.9 kernel. It deals with generic block devices and uses the device mapper framework. While there have been a few other similar tools flying around, since this one has been adopted into the kernel it looks like this will be the one that […]

The 2012 Leap Second on Linux

Sheeri K. Cabral at the Mozilla Foundation wrote about an issue with the June 30th 2012 leap second affecting at least MySQL, Java and Minecraft servers. It now appears that the underlying cause is a Linux kernel bug, as noted by John Stultz (IBM) on the Linux Kernel mailing list, and the team Sheeri is part […]

Storage Miniconf Deadline Extended!

The linux.conf.au organisers have given all miniconfs an additional few weeks to spruik for more proposal submissions, huzzah! So if you didn’t submit a proposal because you weren’t sure whether you’d be able to attend LCA2010, you now have until October 23 to convince your boss to send you and get your proposal in.

Storage miniconf at linux.conf.au 2010

Since you were going to linux.conf.au 2010 in Wellington, NZ anyway in January of next year, you should submit a proposal to speak at the data storage and retrieval miniconf. If you have something to say about storage hardware, file systems, raid, lvm, databases or anything else linux or open source and storage related, please […]

Tool of the day: inotify

I was actually exploring inotify-tools for something else, but they can also be handy for seeing what goes on below a mysqld process. inotify hooks into the filesystem handlers, and sees which files are accessed. You can then set triggers, or just display a tally over a certain period. It has been a standard Linux […]

Book: Pro Linux System Administration

Peter Lieverdink (also known as cafuego on IRC/identi.ca, engineer on OurDelta builds and for Open Query) has co-authored a book that’s available since Monday. The title is Pro Linux System Administration published by Apress. These days some people don’t want to bother with system administration, and either hire or outsource. Others want to find out more […]

Update: MySQL tmpdir on tmpfs

Followup on Experiment: MySQL tmpdir on tmpfs, about tmpdir=/dev/shm in my.cnf (it’s not a dynamic variable that can be set at runtime). It’s working well, also confirmed by comments from others that they’ve been using it for a while. This particular setting is Linux specific. On Solaris, the default /tmp is already on a tmpfs so […]

Experiment: MySQL tmpdir on tmpfs

In MySQL, the tmpdir path is mainly used for disk-based sorts (if the sort_buffer_size is not enough) and disk-based temp tables. The latter cannot always be avoided even if you made tmp_table_size and max_heap_table_size quite large, since MEMORY tables don’t support TEXT/BLOB type columns, and also since you just really don’t want to run the […]