On Sat, Jul 14, 2012 at 9:02 PM, Duncan <1i5t5.dun...@cox.net> wrote: > Rich Freeman posted on Sat, 14 Jul 2012 19:57:41 -0400 as excerpted: >> >> I doubt anybody has tried it, so you'll have to experiment. > > "Anybody" /anybody/, or "anybody" on gentoo? FWIW, there are people > running it in general (IIRC much of the discussion was on Debian, some on > Fedora/RH), but I didn't see anything out there written from a gentoo > perspective.
I'd think that a source vs binary distro wouldn't matter much as far as a tmpfs-based root goes. That is, if you're taking about an empty root that you just mount stuff on top of. >> I imagine you could do it with a dracut module. There is already a >> module that will parse a pre-boot fstab (/etc/fstab.sys). The trick is >> that you need to create the root filesystem and the mountpoints within >> it first. The trick will be how dracut handles not specifying a root >> filesystem. > > While I do know dracut is an initr* helper, you just made me quite aware > of just how much research I'd have to do on the topic. =:^\ I wasn't > aware dracut even /had/ modules, while you're referring to them with the > ease of familiarity... See: http://rich0gentoo.wordpress.com/2012/01/21/a-quick-dracut-module/ Much of dracut's power comes from its modules. Again, I'm not sure how it handles not being given a root at all. You'd have to build a root, or extract it from a tarball/etc. Looking at the docs it seems like you'd need a hook for the cmdline stage that sets rootok (assuming it gets that far without a root, or if you set it to something like root=TMPFS). Then you'd install a hook to mount to mount the tmpfs, and then use the fstab-sys module to mount everything else. You'd need to create mountpoints for everything of course, and not just the boot-critical stuff, since otherwise openrc won't be able to finish mounting mounting everything. > > The big problem with btrfs subvolumes from my perspective is that they're > still all on a single primary filesystem, and if that filesystem develops > problems... all your eggs/data are in one big basket, good luck if the > bottom drops out of it! Maybe, but does it really buy you much if you only lose /lib, and not /usr? I guess it is less data to restore from backup, but... The beauty of btrfs subvolumes is that it lets you manage all your storage as a single pool, even more flexibly than LVM. Sure, chopping it up does reduce the impact of failure a bit, but I'd hate to have to maintain such a system. Filesystem failure should be a very rare occurance for any decent filesystem (of course, this is why I won't be using btrfs in production for a while). Rich
