Index of /ulrich/mobile-update

Name	Last modified	Size

Parent Directory		-
literature/	23-Jun-1999 14:39	-
mobile-update-0.tgz	11-Mar-1998 21:35	9.6K
mobile-update-1.tgz	19-Mar-1999 15:20	9.6K

Mobile update daemon

(In case of download problems, use anonymous ftp: ftp.complang.tuwien.ac.at/pub/ulrich/mobile-update)

mobile-update is a drop in replacement for the Linux update daemon to minimize disk spin ups and reduce disk uptime. It flushes buffers only when other disk activity is present. To ensure a consistent file system call sync(8) manually. Otherwise files may be lost on power failure. mobile-update does not use APM. So it works also on older systems.

use Cntrl-Alt-Del and the menue to invoke sync:

/etc/inittab:ca::ctrlaltdel:/bin/sync
~/.fvwmrc:Popup "Utilities"
~/.fvwmrc:	Exec "Sync" sync

Versions

* Original update daemon by Torsten Poulin

0 mobile modifications by Ulrich Neumerkel

1 cleanups by Andreas Mohr, Matthias Knol

Further plans

Different policies for AC on-line/off-line (needs APM support). Just got a new machine (Sony VAIO PCG-737) with it. There, the disk is again the loudest component.
Dan Christensen's suggestions to have more safety without user interaction. (Current worst case scenario: No disk access for weeks, and then the system is switched off...). Maybe regular updates should be enabled when on-line (but then, this is noisy...). Also try to sort out very unimportant writes like last access info etc.
use (something equivalent to) /sbin/hdparm -C /dev/hda to check the real status of disk (currently we only guess the status indirectly and hdparm -C cannot be used directly because this will cause an update of its access time...).
Look into the update for newer distributions (written by Eric Youngdale, Phil Bostley, Daniel Quinlan). Eric Youngdale Phil Bostley Daniel Quinlan
Find a good policy to avoid that the disk spins down and up continuously. This may reduce disk lifetime, and is also annoying to listen to. (Maybe increase spin down time when next access was too soon etc. and decrease it when, well... there's some literature about that)
Ensure that there is a spin down at least every X hours. (Rumours are that certain disks for portables need to park/spin down etc. form time to time).
Writes to swap space
A tool to trace easily the reason for spin ups.
Look at OpenBIOS (/dev/bios), Phoenix. (PhoenixBIOS 4.0 Release 6.0.B, BIOS Version R0111S3).