Dear systemd-devel list, I'm trying to debug the following problem:
For some unknown reason, /proc and /sys get unmounted during boot from a NFS mounted rootfs. Booting to an emergency shell, I can observe them disappear by first calling mount (which reads from /proc due to /etc/mtab being a symlink) and then calling "ls /proc". After calling ls, mount obviously complains about not being able to read mtab, instead of listing the mounts as before. A 2nd or 3rd call of mount before listing /proc works fine, too. This happens on an gentoo-amd64 system using kernel 3.18.5 and systemd-218. Booting with debug options yields no further information, no new messages appear while the debug shell is running and the messages before are not very interesting (as far as I can tell) [--> end of mail]. Booting the very same installation with the same initramfs from a disk works fine, even when forcing the disk to be mounted read-only, as the NFS share is. About a year ago, I installed a number-crunching cluster, whose nodes are running from a read-only NFS share. This was also a gentoo based system running systemd-215. Stuff works fine, there. Thus, I tried version 215 and even 216 for the new installation, too, yet without success. What might cause systemd to unmount /proc and /sys? Or might this issue not be related to systemd at all? Thanks for your input! Olaf ############# [....] [leading kernel messages skipped] [ 17.857082] systemd[1]: Mounting cgroup to /sys/fs/cgroup/cpu,cpuacct of type cgroup with options cpu,cpuacct. [ 17.857308] systemd[1]: Mounting cgroup to /sys/fs/cgroup/memory of type cgroup with options memory. [ 17.857505] systemd[1]: Mounting cgroup to /sys/fs/cgroup/devices of type cgroup with options devices. [ 17.857694] systemd[1]: Mounting cgroup to /sys/fs/cgroup/net_cls of type cgroup with options net_cls. [ 17.857882] systemd[1]: Mounting cgroup to /sys/fs/cgroup/cpuset of type cgroup with options cpuset. [ 17.858073] systemd[1]: Mounting cgroup to /sys/fs/cgroup/freezer of type cgroup with options freezer. [ 17.858258] systemd[1]: Mounting cgroup to /sys/fs/cgroup/blkio of type cgroup with options blkio. [ 17.858479] systemd[1]: systemd 218 running in system mode. (+PAM -AUDIT -SELINUX +IMA -APPARMOR +SMACK -SYSVINIT +UTMP -LIBCRYPTSETUP -GCRYPT -GNUTLS +ACL +XZ -LZ4 +SECCOMP +BLKID -ELFUTILS +KMOD -IDN) [ 17.860362] systemd[1]: Detected architecture 'x86-64'. [ 17.879066] systemd[1]: Using cgroup controller name=systemd. File system hierarchy is at /sys/fs/cgroup/systemd. [ 17.879273] systemd[1]: Installed release agent. [ 17.879434] systemd[1]: Set up TFD_TIMER_CANCEL_ON_SET timerfd. [ 17.882492] systemd[160]: Spawned /usr/lib/systemd/system-generators/systemd-debug-generator as 161. [ 17.882782] systemd[160]: Spawned /usr/lib/systemd/system-generators/systemd-gpt-auto-generator as 162. [ 17.883095] systemd[160]: Spawned /usr/lib/systemd/system-generators/systemd-getty-generator as 163. [ 17.883403] systemd[160]: Spawned /usr/lib/systemd/system-generators/systemd-system-update-generator as 164. [ 17.883685] systemd[160]: Spawned /usr/lib/systemd/system-generators/gentoo-local-generator as 165. [ 17.883969] systemd[160]: Spawned /usr/lib/systemd/system-generators/systemd-efi-boot-generator as 166. [ 17.884273] systemd[160]: Spawned /usr/lib/systemd/system-generators/systemd-fstab-generator as 167. [ 17.884565] systemd[160]: Spawned /usr/lib/systemd/system-generators/systemd-hibernate-resume-generator as 168. [ 17.923410] systemd-efi-boot-generator[166]: Not an EFI boot, exiting. [ 17.923445] systemd-fstab-generator[167]: Parsing /etc/fstab [ 17.925772] systemd-fstab-generator[167]: Found entry what=134.96.30.183:/exports/raid/client/distribution/gentoo-amd64 where=/ type=nfs nofail=no noauto=no [ 17.926259] systemd-gpt-auto-generator[162]: Not a EFI boot, not creating root mount. [ 17.987813] systemd-gpt-auto-generator[162]: Root file system not on a (single) block device. [ 17.987848] systemd-fstab-generator[167]: Found entry what=home-srv:/home where=/home type=nfs nofail=yes noauto=no [ 17.988250] systemd[160]: /usr/lib/systemd/system-generators/systemd-gpt-auto-generator succeeded. [ 17.988422] systemd[160]: /usr/lib/systemd/system-generators/systemd-hibernate-resume-generator succeeded. [ 17.988582] systemd[160]: /usr/lib/systemd/system-generators/systemd-debug-generator succeeded. [ 17.988745] systemd[160]: /usr/lib/systemd/system-generators/systemd-getty-generator succeeded. [ 17.988900] systemd[160]: /usr/lib/systemd/system-generators/systemd-system-update-generator succeeded. [ 18.090371] systemd[160]: /usr/lib/systemd/system-generators/gentoo-local-generator succeeded. [ 18.090528] systemd[160]: /usr/lib/systemd/system-generators/systemd-fstab-generator succeeded. [ 18.090680] systemd[160]: /usr/lib/systemd/system-generators/systemd-efi-boot-generator succeeded. [ 18.090976] systemd[1]: /usr/lib/systemd/system-generators succeeded. [ 18.091723] systemd[1]: Looking for unit files in (higher priority first): [ 18.091833] systemd[1]: /etc/systemd/system [ 18.091931] systemd[1]: /run/systemd/system [ 18.092029] systemd[1]: /run/systemd/generator [ 18.092128] systemd[1]: /usr/local/lib/systemd/system [ 18.092230] systemd[1]: /usr/lib64/systemd/system [ 18.092330] systemd[1]: /lib/systemd/system [ 18.092428] systemd[1]: SysV init scripts and rcN.d links support disabled [ 18.129877] systemd[1]: Failed to load configuration for plymouth-start.service: No such file or directory [ 18.135713] systemd[1]: Failed to load configuration for syslog.service: No such file or directory [ 18.159901] systemd[1]: Failed to load configuration for auditd.service: No such file or directory [ 18.186044] systemd[1]: Using notification socket /run/systemd/notify [ 18.186166] systemd[1]: Successfully created private D-Bus server. [ 18.186275] systemd[1]: tmp.mount changed dead -> mounted [ 18.186397] systemd[1]: var.mount changed dead -> mounted [ 18.186507] systemd[1]: -.mount changed dead -> mounted [ 18.186619] systemd[1]: Activating default unit: emergency.target [ 18.186727] systemd[1]: Trying to enqueue job emergency.target/start/isolate [ 18.186882] systemd[1]: Installed new job emergency.service/start as 2 [ 18.187000] systemd[1]: Installed new job -.slice/start as 5 [ 18.187105] systemd[1]: Installed new job emergency.target/start as 1 [ 18.187213] systemd[1]: Installed new job system.slice/start as 4 [ 18.187324] systemd[1]: Enqueued job emergency.target/start as 1 [ 18.187431] systemd[1]: Loaded units and determined initial transaction in 305ms. [ 18.187610] systemd[1]: Child 159 (switch_root) died (code=exited, status=0/SUCCESS) [ 18.187818] systemd[1]: Received SIGCHLD from PID 160 (n/a). [ 18.187935] systemd[1]: Starting Root Slice. [ 18.188210] systemd[1]: -.slice changed dead -> active [ 18.188314] systemd[1]: Job -.slice/start finished, result=done [ 18.188445] systemd[1]: Created slice Root Slice. [ 18.188555] systemd[1]: Starting System Slice. [ 18.188740] systemd[1]: system.slice changed dead -> active [ 18.188845] systemd[1]: Job system.slice/start finished, result=done [ 18.188958] systemd[1]: Created slice System Slice. [ 18.189066] systemd[1]: Starting Emergency Shell... [ 18.189337] systemd[1]: About to execute: /bin/plymouth quit [ 18.189562] systemd[1]: Forked /bin/plymouth as 170 [ 18.189725] systemd[1]: emergency.service changed dead -> start-pre [ 18.189834] systemd[1]: Job emergency.service/start finished, result=done [ 18.189954] systemd[1]: Started Emergency Shell. [ 18.190078] systemd[1]: Starting Emergency Mode. [ 18.190178] systemd[1]: emergency.target changed dead -> active [ 18.190291] systemd[1]: Job emergency.target/start finished, result=done [ 18.190406] systemd[1]: Reached target Emergency Mode. [ 18.190526] systemd[1]: Startup finished in 17.677s (kernel) + 352ms (userspace) = 18.030s. [ 18.191601] systemd[170]: Executing: /bin/plymouth quit [ 18.191996] systemd[170]: Failed at step EXEC spawning /bin/plymouth: No such file or directory [ 18.192354] systemd[1]: Received SIGCHLD from PID 170 ((plymouth)). [ 18.192479] systemd[1]: Child 170 ((plymouth)) died (code=exited, status=203/EXEC) [ 18.192645] systemd[1]: Child 170 belongs to emergency.service [ 18.192754] systemd[1]: emergency.service: control process exited, code=exited status=203 [ 18.192959] systemd[1]: emergency.service running next control command for state start-pre [ 18.193145] systemd[1]: About to execute: /bin/echo -e 'Welcome to emergency mode! After logging in, type "journalctl -xb" to view\nsystem logs, "systemctl reboot" to reboot, "systemctl default" or ^D to\ntry again to boot into default mode.' [ 18.193525] systemd[1]: Forked /bin/echo as 172 [ 18.193998] systemd[172]: Executing: /bin/echo -e 'Welcome to emergency mode! After logging in, type "journalctl -xb" to view\nsystem logs, "systemctl reboot" to reboot, "systemctl default" or ^D to\ntry again to boot into default mode.' [ 18.224074] systemd[1]: Accepted new private connection. [ 18.224228] systemd-cgroups-agent[171]: Sent message type=signal sender=n/a destination=n/a object=/org/freedesktop/systemd1/agent interface=org.freedesktop.systemd1.Agent member=Released cookie=1 reply_cookie=0 error=n/a [ 18.224963] systemd[1]: Accepted new private connection. [ 18.225097] systemd[1]: Got message type=signal sender=n/a destination=n/a object=/org/freedesktop/systemd1/agent interface=org.freedesktop.systemd1.Agent member=Released cookie=1 reply_cookie=0 error=n/a [ 18.225113] systemd-cgroups-agent[173]: Sent message type=signal sender=n/a destination=n/a object=/org/freedesktop/systemd1/agent interface=org.freedesktop.systemd1.Agent member=Released cookie=1 reply_cookie=0 error=n/a [ 18.225654] systemd[1]: Got disconnect on private connection. [ 18.226067] systemd[1]: Got message type=signal sender=n/a destination=n/a object=/org/freedesktop/systemd1/agent interface=org.freedesktop.systemd1.Agent member=Released cookie=1 reply_cookie=0 error=n/a [ 18.226357] systemd[1]: Got disconnect on private connection. [ 18.359352] systemd[1]: Received SIGCHLD from PID 172 (echo). [ 18.359477] systemd[1]: Child 172 (echo) died (code=exited, status=0/SUCCESS) [ 18.359609] systemd[1]: Child 172 belongs to emergency.service [ 18.359719] systemd[1]: emergency.service: control process exited, code=exited status=0 [ 18.359938] systemd[1]: emergency.service got final SIGCHLD for state start-pre [ 18.360112] systemd[1]: About to execute: /bin/sh -c '/sbin/sulogin; /usr/bin/systemctl --fail --no-block default' [ 18.360376] systemd[1]: Forked /bin/sh as 176 [ 18.360596] systemd[1]: emergency.service changed start-pre -> running [ 18.360817] systemd[176]: Executing: /bin/sh -c '/sbin/sulogin; /usr/bin/systemctl --fail --no-block default' [ 18.405949] systemd[1]: Accepted new private connection. [ 18.406092] systemd-cgroups-agent[175]: Sent message type=signal sender=n/a destination=n/a object=/org/freedesktop/systemd1/agent interface=org.freedesktop.systemd1.Agent member=Released cookie=1 reply_cookie=0 error=n/a [ 18.406816] systemd[1]: Accepted new private connection. [ 18.406943] systemd[1]: Got message type=signal sender=n/a destination=n/a object=/org/freedesktop/systemd1/agent interface=org.freedesktop.systemd1.Agent member=Released cookie=1 reply_cookie=0 error=n/a [ 18.406944] systemd-cgroups-agent[178]: Sent message type=signal sender=n/a destination=n/a object=/org/freedesktop/systemd1/agent interface=org.freedesktop.systemd1.Agent member=Released cookie=1 reply_cookie=0 error=n/a [ 18.407478] systemd[1]: Got disconnect on private connection. [ 18.407883] systemd[1]: Got message type=signal sender=n/a destination=n/a object=/org/freedesktop/systemd1/agent interface=org.freedesktop.systemd1.Agent member=Released cookie=1 reply_cookie=0 error=n/a [ 18.408145] systemd[1]: Got disconnect on private connection _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel