On Sat, 2004-11-13 at 12:18 -0500, Owen Taylor wrote:
Ideally, system boot would involve a 3-4 second sequential read of
around 100 megabytes of data from the hard disk,
make that 7 seconds..
Note: I did this experiment about a year ago, during boot first read
everything into cache and then do the rest of boot basically without
disk IO (there are some writes but that's async).
The total time to boot did not decrease ......
CPU utilization would
be parallelized with that, and all queries on external systems would
be asynchronous ... startup continues and once the external system
responds, the system state is updated. Plausibly the user could start
work under 10 seconds on this ideal system.
given the 7 second disk read time... 10 seconds is a bit unrealistic.
One of the critical paths will be getting an IP address and mounting the
/home dir over nfs... ethernet negotiation can easily be 10 seconds
already with gige, and DHCP is depending on that to complete before it
can get a lease.
One of the things we should investigate is just reduce the shere number
of different files that get opened.... its about 11000 iirc right now.