Hi, On Mon, Mar 10, 2003 at 03:03:18PM +0000, Miquel van Smoorenburg wrote: > Perhaps it is time for a /var/bootstate (with a better name though) > on which during early boot a shmfs is mounted, and as soon as > /var becomes available for mounting is copied over to the real > /var/bootstate and unmounted. > > On shutdown this should be reversed ofcourse, so a seperate > directory /var/bootstate is needed - you can't copy /var/state > to shmfs in its entirity, it would potentially be way to big. Good idea, but why copy it over and unmount it at startup instead of shutdown? I use something like that on my notebook to prevent things like ntpd's drift file from spinning up the disk all the time: I have /tmp as ext2 on a ramdisk (could just as well be shmfs though) and have a /tmp/preserved which I create from /var/tmp-preserved at bootup and copy back to /var/tmp-preserved at shutdown, and have /var/lib/ntp symlinked to /var/tmp-preserved/ntp. Of course, using /tmp in such a way goes a bit far, but why not do it like this then: * keep /tmp as it is now; * keep /var as it is now; * add /mem, which is RAM-based, writable /very/ early, and initialised in full from /var/mem at bootup, allowing the admin to define a desired initial state; * have part of it, eg. /mem/preserved, written back to /var/mem/preserved at shutdown. Pidfiles, locks, ifstate, dhcp stuff, mtab, etc. that now need cleaning up at boot time would be perfect candidates for /mem, things like ntp.drift could go in /mem/preserved, and some parts parts of /var/state could be moved to either. This is good for your disks, good for your batteries, simplifies state cleanup at startup, and solves the writable-etc-or-no-networked-var issue with ifstate to boot. It "just" needs to be added to FHS. I think /mem/ is cleaner than /var/mem, because the latter either requires /var to be already mounted readonly, which sort of defeats the purpose, or a lot of messy and fragile data movements at startup. Cheers, Emile. -- E-Advies / Emile van Bergen | emile@e-advies.nl tel. +31 (0)70 3906153 | http://www.e-advies.nl
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