On Mon, Jul 9, 2012 at 10:51 AM, Tom Gundersen <teg@xxxxxxx> wrote: > On Mon, Jul 9, 2012 at 10:10 AM, Damjan <gdamjan@xxxxxxxxx> wrote: >> Has anyone done any research on stateless ArchLinux instances. >> >> A stateless Arch would be one where the root filesystem is mounted read-only >> and nothing changes there. Thus it can mounted over network (using NFS, NBD >> and similar) by several, diskless, PCs at the same time. >> >> I plan to have per user HOME directories on a server (again NFS or similar), >> and users credentials in LDAP. >> >> /var/run beeing a link to a tmpfs /run, and by using systemd-journal without >> /var/log/journal (it will store logs in memory) a lot of things avoid >> hitting the disk already. >> >> I'd use connman for handling the net connection and it seems to require a >> writable /var/lib/connman/ >> >> >> Anyone with any experience with this? > > I have been working towards initscripts allowing this, and various > upstreams (such as util-linux) should also support this setup. That > said, I have not actually tested this to any great extent, so don't > know how well it will work (feedback very welcome!). > > What should work (but might not!): /etc and /usr (and /lib, /sbin, > /bin) should be able to be mounted read-only. I expect you'll have to > figure out how to deal with /etc/resolv.conf, I wonder if > NetworkManager has learnt how to deal with this gracefully since I > last checked... > > What will not work: as Rodrigo said, you'll still need /var to be > mounted read-write, the point of /var is for applications to be able > to write to it. Moreover, /var must be unique to each installation, > and cannot be shared (you can put it on an NFS share though, just make > sure you have one for each machine). Moreover, even if /etc/ is > mounted read-only, you probably want one per machine. You might get > away with sharing it, but then all your hostnames will be the same for > instance. Importantly: you don't want /etc/machine-id to be shared by > different machines (as it needs to be unique). If you do decide to > share /etc, you can replace /etc/machine-id by an empty file and > systemd will create a random one at every boot (in /run) and use that > instead, so you should be fine in this respect. > > HTH, > > Tom Reference for the machine-id stuff: <http://0pointer.de/public/systemd-man/machine-id.html> or machine-id(5) if you have access to a systemd system. -t
