To speed the boot of Fedora, the taken approach is to readahead the files needed by the daemons/tools run during boot. This approach works well but the actual approach is to pre-load some files from a static defined file. (This is accomplished by /etc/init.d/readahead which reads files from /etc/readahead.files)
There is IMHO at least 2 problems:
- When the boot process change, either by removing/adding services, the fiels that must be readahead change. But the readahead.files don't.
- The readahead process don't read the files in the best order to minimize the head movement on the hard disk
- The readahead process don't rearrange the files on disk so the readahead process can be quicker.
Why not implement a dynamic mechanism to know which files need to be read in readahead?
- End of kernel init
- Register a (KProbes or LSM?) hook that listen to which files are read
- Boot the system
- End of system boot, read the files that were read during boot itself.
- Update the readahead.files file so the readahead could be quicker.
A second step could be to rearrange the files so the readahead could read them without too much head movemement on the HD. Perhaps with help of e2fsdefrag?
Do you have any comment? -jec
-- Jean-Eric Cuendet Riskpro Technologies SA Av du 14 avril 1b, 1020 Renens Switzerland Principal: +41 21 637 0110 Fax: +41 21 637 01 11 Direct: +41 21 637 0123 E-mail: jean-eric.cuendet at rptec.ch http://www.rptec.ch --------------------------------------------------------
