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diff --git a/SW/pmset-linux-workaround/document.en.rest.txt b/SW/pmset-linux-workaround/document.en.rest.txt new file mode 100644 index 0000000..c510d0f --- /dev/null +++ b/SW/pmset-linux-workaround/document.en.rest.txt @@ -0,0 +1,63 @@ +=================================== + Waking up a Mac at a certain time +=================================== +:CreationDate: 2008-10-02 18:10:00 +:tags: software + +I have an old G3 iBook that I use to perform backups (using +rsnapshot_). The scripts that run the backup process start it as soon +as the machine wakes up, and put it back to sleep afterwards (using +pbbuttonsd_). Problem: every time I want to run a backup, I have to +manually wake the machine up (by pressing the power button, or opening +the lid). Clearly I'd like for the backup to happen ever if I forget, +or if I'm not at home. + +How it works on `Mac OS X` +========================== + +If that iBook were running `Mac OS X`, it would be easy:: + + pmset repeat wake MTWRFSU 05:00:00 + +and it would wake up automatically, every day at 5 in the morning +(those letters are ugly abbreviations for the English names of the +days of the week). + +But I have Linux running on that machine! + +Can it be done in Linux? +======================== + +It seems it can't: ``drivers/macintosh/via-pmu.c``, the Power +Management Unit's driver, implements only a couple of functions. + +How did I manage? +================= + +Using a trick. I started with the `Mac OS X` 10.4 installation disk, +opened a Terminal, and run ``pmset``. Which did not work, giving me an +error 0xe00002bc. Digging a bit on the Web we discover that such error +means more or less "I can't write a file". *Write a file*? Whoever +asked for such a thing? + +Reading more attentively the documentation_ for ``pmset``, we discover +that it writes a couple of file in +``/Library/Preferences/SystemConfiguration``. Obviously, having booted +off a CD, that directory is read-only. + +I can't find a way to create a ``tmpfs`` or similar, so I take a USB +stick and try to mount it. It does not work: there are no drivers for +`FAT`, or something. OK, I just format it `HFS`, and finally I mount +it:: + + mount -o union -t hfs /dev/disk5s1 /Library/Preferences/SystemConfiguration + +I re-run ``pmset``, nd finally the configuration is set. + +.. _rsnapshot: http://www.rsnapshot.org/ + +.. _pbbuttonsd: http://pbbuttons.berlios.de/ + +.. _documentazione: + http://developer.apple.com/documentation/Darwin/Reference/ManPages/man1/pmset.1.html + |