On Tuesday, 19 September 2017 20:03:46 UTC+3, Britton Kerin wrote: > > On Mon, Sep 18, 2017 at 2:21 AM, Tarmo Kuuse <[email protected] > <javascript:>> wrote: > > On Sunday, 17 September 2017 10:45:16 UTC+3, Britton Kerin wrote: > >> > >> On Wed, Sep 6, 2017 at 7:59 AM, Tarmo Kuuse <[email protected]> > wrote: > >> > On Tuesday, September 5, 2017 at 1:45:05 AM UTC+3, Britton Kerin > wrote: > >> >> > >> >> Any help modifying the above recipe or pointer to how to do it these > >> >> days would be appreciated. > >> > > >> > > >> > I just declare the root file system as read-only in fstab and create > >> > some > >> > ramdisks for stuff that needs to be writable. > >> > > >> > LABEL=rootfs / ext4 ro,noatime,errors=remount-ro 0 1 > >> > debugfs /sys/kernel/debug debugfs defaults 0 0 > >> > tmpfs /var/log tmpfs defaults,noatime,nosuid,mode=0777,size=128M > 0 > >> > 0 > >> > tmpfs /var/tmp tmpfs defaults,noatime,nosuid,size=16M 0 0 > >> > tmpfs /tmp tmpfs defaults,noatime,nosuid,size=128M 0 0 > >> > > >> > Service generic-board-startup (a.k.a. > >> > /opt/scripts/boot/generic-startup.sh) > >> > must run once with a writable root to set up a bunch of stuff (on > later > >> > boots it complains, but it doesn't seem to matter). After that you're > >> > stuck > >> > hacking all the software which expects to be able to write to disk. > For > >> > a > >> > working network, "/etc/resolv.conf" needs symlinking to a writable > >> > location. > >> > Many services expect to persistently store their stuff under > "/var/lib". > >> > > >> > I've used tmpfiles.d to create required symlinks, e.g. > >> > > >> > $ cat /etc/tmpfiles.d/10-ro-symlinks.conf > >> > L+ /etc/resolv.conf - - - - /var/run/symlinks/etc/resolv.conf > >> > L+ /etc/ppp/resolv.conf - - - - /var/run/symlinks/etc/ppp/resolv.conf > >> > >> Hmm having tried this I don't get it. This fragment seem to be > assuming > >> that: > >> > >> * the dirs /var/run/symlinks/etc etc. are created somehow, maybe > >> with a d line in the same file? > >> > >> * the link target files /var/run/symlinks/etc/resolv.conf exist, > >> I guess they can just be empty as connection manager is going to fix > >> them up for me anyway? > >> > >> Thanks, > >> Britton > > > > > > Right. I wanted to emphasize only the important lines, but prerequisites > are > > important too :) > > > > Here's the full file > > > > #Type Path Mode UID GID Age Argument > > d /var/run/symlinks 0755 - - - > > d /var/run/symlinks/etc 0755 - - - > > d /var/run/symlinks/etc/ppp 0755 - - - > > f /var/run/symlinks/etc/resolv.conf 0755 - - - > > f /var/run/symlinks/etc/ppp/resolv.conf 0755 - - - > > > > # NB! Connman might override this by linking > > "/usr/lib/tmpfiles.d/connman_resolvconf.conf" to > "/run/connman/resolv.conf" > > L+ /etc/resolv.conf - - - - /var/run/symlinks/etc/resolv.conf > > L+ /etc/ppp/resolv.conf - - - - /var/run/symlinks/etc/ppp/resolv.conf > > Ok this work, thanks so much. There are still a couple things I don't > get though: > > * I notice in your original replay you don't have a tmpfs for /run > (which is sym linked to from /var/run). So I wonder how the dirs > and files you create from /etc/tmpfiles.d/10-ro-symlinks.conf are > getting created, since I would think they would be on the (read-only) > root file system. Is there something missing from the fstab you > originally showed? I included this line as well: > > tmpfs /run tmpfs defaults,noatime,nosuid,size=16M 0 0 > > I haven't gone back and tested without it, so maybe it works as you > show and I just don't understand how. >
The Debian images from Robert already have that set up. "/run" is a tmpfs and "/var/run" is symlink pointing to it. > * I end up with a rw tmpfs for /root (root home dir), as shown by > cat /etc/mtab (last line): > > root@bbone217slave:/etc# cat /etc/mtab > sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0 > proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0 > udev /dev devtmpfs rw,relatime,size=10240k,nr_inodes=55575,mode=755 0 > 0 > devpts /dev/pts devpts > rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0 > tmpfs /run tmpfs rw,nosuid,noatime,size=16384k,mode=755 0 0 > /dev/mmcblk1p1 / ext4 ro,noatime,errors=remount-ro,data=ordered 0 0 > securityfs /sys/kernel/security securityfs > rw,nosuid,nodev,noexec,relatime 0 0 > tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0 > tmpfs /run/lock tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k 0 0 > tmpfs /sys/fs/cgroup tmpfs ro,nosuid,nodev,noexec,mode=755 0 0 > cgroup /sys/fs/cgroup/systemd cgroup > rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd > > > 0 0 > cgroup /sys/fs/cgroup/blkio cgroup > rw,nosuid,nodev,noexec,relatime,blkio 0 0 > cgroup /sys/fs/cgroup/net_cls,net_prio cgroup > rw,nosuid,nodev,noexec,relatime,net_cls,net_prio 0 0 > cgroup /sys/fs/cgroup/devices cgroup > rw,nosuid,nodev,noexec,relatime,devices 0 0 > cgroup /sys/fs/cgroup/cpuset cgroup > rw,nosuid,nodev,noexec,relatime,cpuset 0 0 > cgroup /sys/fs/cgroup/cpu,cpuacct cgroup > rw,nosuid,nodev,noexec,relatime,cpu,cpuacct 0 0 > cgroup /sys/fs/cgroup/perf_event cgroup > rw,nosuid,nodev,noexec,relatime,perf_event 0 0 > cgroup /sys/fs/cgroup/pids cgroup rw,nosuid,nodev,noexec,relatime,pids > 0 0 > cgroup /sys/fs/cgroup/freezer cgroup > rw,nosuid,nodev,noexec,relatime,freezer 0 0 > cgroup /sys/fs/cgroup/memory cgroup > rw,nosuid,nodev,noexec,relatime,memory 0 0 > systemd-1 /proc/sys/fs/binfmt_misc autofs > rw,relatime,fd=30,pgrp=1,timeout=0,minproto=5,maxproto=5,direct 0 0 > mqueue /dev/mqueue mqueue rw,relatime 0 0 > debugfs /sys/kernel/debug debugfs rw,relatime 0 0 > fusectl /sys/fs/fuse/connections fusectl rw,relatime 0 0 > configfs /sys/kernel/config configfs rw,relatime 0 0 > tmpfs /var/log tmpfs rw,nosuid,noatime,size=131072k,mode=777 0 0 > tmpfs /var/tmp tmpfs rw,nosuid,noatime,size=16384k 0 0 > tmpfs /tmp tmpfs rw,nosuid,noatime,size=131072k 0 0 > tmpfs /root tmpfs rw,relatime 0 0 > > I don't know what mechanism causes this? It presumably is why my old > way of doing this once worked. > No idea. I don't have that last entry for /root. -- Kind regards, Tarmo Kuuse -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/00ba34c5-65cf-4d61-8bd8-28e54930f513%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
