On Thu, Apr 21, 2005 at 03:20:53PM +0200, Arjan van de Ven wrote:
On Thu, 2005-04-21 at 15:01 +0200, Jean-Eric Cuendet wrote:
> Hi,
> 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
this one is easy to fix btw; I wrote a small tool a while ago (and
posted to the list) to sort the file in disk order
Something I noticed a few days ago was that running filefrag
on a freshly installed system shows a lot of files using multiple
extents (sometimes dozens), rather than a single extent.
I've no idea how much difference this would make in the real-world,
(maybe none due to the drive internal read-ahead) but it was surprising
to see bits of openoffice using up 80-90 extents for eg.
Dave