Ext4 Performance Improvements

In order to speed up the general performance of my personal computer I put an Intel X25-M SSD into it some time ago and made sure that most binaries that are needed to start up Linux are loaded from the SSD. I could not go without a conventional hard disk, though, because the storage capacity of typical SSDs (or the budget that I am willing to spend) is still too limited. While boot times already improved dramatically after adding the SSD, mounting the file systems located on my conventional hard disk was still limiting the overall speed of the boot process.

That was when I read about the performance improvements introduced by the ext4 file system.

So, today I migrated my /var and /home file system from ext3 to ext4 (which explains my previous blog post) and the results are pretty stunning. Ext4 seems to have improved the time it takes to mount a clean file system by an order of magnitude. Combined with the SSD performance boost the overall startup now nearly feels like “instant on” and the kdm log-on screen shows up in under five seconds after Linux has started booting.

If there was just a way to speed up the BIOS POST procedure (which now actually takes longer than starting up the OS)…