Using tmpfs for Security and Speed

I have 3.9GBs of RAM of which Ubuntu 10.04 (Lucid Lynx) hardly touches more than 512MBs so I'm going to move all my temporary files to RAM. This will result in 2 things:

• Reading and writing temporary files will be much faster.
• Temporary files will be more securely removed on shutdown.

Writeback Journalling

ext3 and ext4 have 3 ways of journalling data: writeback, ordered and journal modes. By default most distros use ordered. However in most cases writeback mode will give faster performance. So I'll show you how to switch over. Check out a more detailed explanation of these journalling options.

atime, relatime and noatime

Most filesystems take note of the last time a file was accessed, this is known as atime. The downside of always knowing when the file was last accessed is that even if you don't change any of the data within the file, the disk still has to write the new atime information. Atime updates are a terrible waste of time. It turns read-only operations into writes just to keep atime up to date. So with the release of the 2.6.20 Linux kernel relatime was introduced. relatime only updates whenever the file data is changed. Atime was still default until the recent release of the 2.6.30 kernel where relatime became the default.