Re: power saving(mobile-update daemon,...)
On Saturday 4 September 1999, at 11 h 12, the keyboard of Werner Heuser
<wehe@snafu.de> wrote:
> the 'dpkg-divert' mechanism. It restored the former
> 'update' package without any problems.
Even better: if you upgrade the original "update" while mobile-update is
installed, it upgrades the copy and, when you remove mobile-update, the
upgraded copy is used. That's one of the thing that make me say that Debian is
much easier to use than any other Linux distribution (as long as you rely on
facts, not on often-repeated marketing speeches).
> 1) How do I know 'mobile-update' works?
> - 'man 8 update' didn't make this clear to me
This version is for mobile computers to reduce power con-
sumption by allowing hard disk spin down extending battery
life. The filesystem buffers are only flushed if the disk
is used for other activity like reading a file or swap-
ping.
Is it not clear? mobile-update checks if the disk already works (by reading
/proc/stat) and, if so, calls sync().
> - /usr/doc/update is empty and /usr/doc/mobile-update is nearly empty
The Web page is referenced in /usr/doc/mobile-update/README.Debian. I'm not
responsible for the "update" package.
Any other question should be directed to the upstream authors.
> - 'kupdate' is running, has this to do with 'update'? and
> couldn't find a manpage
No idea.
> 2) How can I measure the result in powersaving easily?
> Maybe I can
> - refresh the battery as much as possible
> - start an infinite benchmark test (which one?)
It needs an interactive test, since it is the most common use of laptops. An
expect script to run emacs?
> - use an 'uptime' daemon to measure the time until
> the machines goes down
> but this seems to long for me. Is there another approach?
Use 'apm -v'. Measure the time it takes to do down from 100% to 90% (warning:
APM is not very precise). It will be faster.
> I want to measure other power saving techniques, too:
They are related.
> - hdparm is a Linux IDE disk utility that lets you set
> spin-down timeouts and other disk parameters.
>
> - mount with 'noatime' option, thanks to Sean 'Shaleh' Perry
mobile-update is almost useless if you don't use the above two (both of them).
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