On Tue, Feb 22, 2011 at 5:07 PM, Lennart Poettering <mzerqung@xxxxxxxxxxx> wrote: > On Tue, 22.02.11 14:51, Josef Bacik (josef@xxxxxxxxxxxxxx) wrote: > >> Hello, >> >> So we're getting close to having a working fsck tool so I wanted to >> take the opportunity to talk about the future of BTRFS in Fedora. >> Coming up in F15 we're going to have the first release of Fedora where >> we don't need the special boot option to have the ability to format >> you filesystem as BTRFS. This is in hopes that we can open it up for >> wider testing before possibly making it the default filesystem. I >> realize we're in the early stages of F15, but since filesystems are >> big and important I'd like to get an idea of the amount of work that >> needs to still be done to get BTRFS in shape for being Fedora's >> default filesystem. So here are my goals >> >> 1) Fedora 16 ships with BTRFS as the default root filesystem. > > Hmm, what are your plans regarding hierarchy layout for this? > > My hope is that one day we can ship a read-only root dir by default, or > more specifically a btrfs file system with three subvolumes in it: one > read-only one mounted to /, and two writable ones mounted to /home and > /var, with /tmp mounted from tmpfs. > Yeah the hope is to separate out various things into different subvolumes so we can have things that can be independently snapshottable things. > We came a long way with supporting read-only root dirs and it should > mostly work now. In F15 for example /etc/mtab is a symlink, and even > smaller stuff like /etc/nologin got moved to /var/run, to make write > accesses to /etc unnecessary during normal operation. /etc/resolv.conf > is the only thing often updated that's left, but with NM using dnsmasq > it's static too. > > By using btrfs subvolumes doing this kind of seperation into writable > and non-writable subtrees we don't have to think anymore about the sizes > for those file systems at install time, since they all live in the same > fs. > > If this is adopted package managers and system configuration UIs would > need to invoke "mount / -o rw,remount" before doing their work. > > So, I'd like to see this implemented one day, maybe the adoption of > btrfs is the right time to push this through too? > > I have not filed a feature page for this, as I am not sure I want to > push this on F16, and I don't even know if people in general are onboard > with this idea. The benefits of this are mostly security and robustness > since we know that the actual subvolume the OS is booted from is always > in a consistent state during operation and cannot normally be > changed. And of course, we get all kind of magic by doing this because > we can easily use snapshots to roll back system upgrades while leaving > /home completely untouched. > > Sorry for hijacking your thread like this, > It's cool, just hilights all the cool stuff we can do with BTRFS :). Thanks, Josef -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
