Ubuntu 9.10 Home Encryption Performance

Last December we had looked at the Ubuntu 9.04 home encryption performance after this feature appeared in a development snapshot as an alternative to those looking for security some of their data but are not looking for completely encrypting the hard drive due to the performance impact or other reasons. The home encryption feature ended up being disabled in Ubuntu 9.04 unless a special boot parameter was used, but it has now reappeared in Ubuntu 9.10.

The home encryption support offered in Ubuntu 9.10 comes with many bug fixes and usability issues compared to what was offered in Ubuntu 9.04. The change-log that details all of the work that has went into the eCryptfs package since Ubuntu 9.04 can be found on Launchpad.net. Additionally, this feature now provides AppArmor rules, enabled shell scripts for localization/translations, and now the SWAP partition is encrypted if using the home directory encryption feature. In Ubuntu 9.04 the SWAP partition was never encrypted if using the home encryption feature, which lowered the level of security that was offered and its benefits. With Ubuntu 9.10 the EXT4 file-system is being used by default, which should lead to difference performance figures from our earlier test runs. As a result we have carried out a new round of Ubuntu home directory encryption testing under an Ubuntu 9.10 development snapshot. This feature is exposed both through Ubuntu's Ubiquity installer as well as through Ubuntu's alternate install CD.

Similar to our last set of home encryption tests, we performed a clean installation of Ubuntu 9.10 and then carried out our Linux benchmarks. After that, we performed another clean installation but this time enabling the home encryption option. The operating system settings were left at their defaults and were maintained the same between testing besides the change in home directory encryption.

With netbooks being quite mobile but often housing personal data, securing this data can be very important. For this round of testing we ran a few profiles from the Phoronix Test Suite on a Dell Inspiron Mini 9. This Dell netbook packs an Intel Atom N270 CPU, an Intel 945GME + ICH7-M motherboard with integrated graphics, 1GB of DDR2 system memory, and a STEC PATA 8GB solid state drive. Our Ubuntu 9.10 snapshot contained the Linux 2.6.31-rc9 kernel, GNOME 2.27.91, X Server 1.6.3, xf86-video-intel 2.8.1, Mesa 7.6-devel, GCC 4.4.1, and the default EXT4 file-system. From the 2.2 Bardu branch of the Phoronix Test Suite we ran a few disk benchmarks -- PostgreSQL pgbench, PostMark, AIO-Stress, IOzone, Dbench, and the Threaded I/O Tester.