Hello, after running several sysinfo FAI_ACTIONs with jessie setups (and "aufs" in the append line), I decided the time has come to switch to Stretch.
I upgraded fai-* to 5.5 from the uni-koeln Stretch repository, copied /etc/fai to /etc/fai-stretch, added a few packages to NFSROOT, and then built the NFS-root following the docs (BTW, page 29 has a small "c" instead of capital "C" in the fai-make-nfsroot example line). A few "error" lines showed up in the log: root@t-pring:/etc/fai-stretch# grep -iC3 error: nfsroot.log Setting up dracut (045+132-1) ... dracut: Generating /boot/initrd.img-4.9.0-5-amd64 /usr/lib/dracut/modules.d/45url-lib/module-setup.sh: line 33: warning: command substitution: ignored null byte in input dracut-install: ERROR: installing '/etc/ssl/certs/ca-certificates.crt' dracut: FAILED: /usr/lib/dracut/dracut-install -D /var/tmp/dracut.Mk2W0u/initramfs /etc/ssl/certs/ca-certificates.crt /usr/lib/dracut/modules.d/45url-lib/module-setup.sh: line 33: warning: command substitution: ignored null byte in input dracut-install: ERROR: installing '/etc/ssl/certs/ca-certificates.crt' dracut: FAILED: /usr/lib/dracut/dracut-install -D /var/tmp/dracut.Mk2W0u/initramfs /etc/ssl/certs/ca-certificates.crt /usr/lib/dracut/modules.d/45url-lib/module-setup.sh: line 33: warning: command substitution: ignored null byte in input dracut-install: ERROR: installing '/etc/ssl/certs/ca-certificates.crt' dracut: FAILED: /usr/lib/dracut/dracut-install -D /var/tmp/dracut.Mk2W0u/initramfs /etc/ssl/certs/ca-certificates.crt Setting up openssl (1.1.0f-3+deb9u1) ... Setting up threeware-control (10.2-1) ... -- Setting up grub-pc (2.02~beta3-5) ... Creating config file /etc/default/grub with new version grub-probe: error: cannot find a device for / (is /dev mounted?). grub-probe: error: cannot find a device for /boot (is /dev mounted?). grub-probe: error: cannot find a device for /boot/grub (is /dev mounted?). Setting up libisccfg140:amd64 (1:9.10.3.dfsg.P4-12.3+deb9u4) ... Setting up emacs25-nox (25.1+1-4+deb9u1) ... update-alternatives: using /usr/bin/emacs25-nox to provide /usr/bin/emacs (emacs) in auto mode - they seem to be sufficiently benign though. With a pxelinux.cfg file: root@t-pring:/srv/fai/tftp/pxelinux.cfg# cat 0A966401 # generated by fai-chboot for host mds-eth0 with IP 10.150.100.1 default fai-generated label fai-generated kernel vulcan-stretch/vmlinuz append initrd=vulcan-stretch/initrd.img ip=dhcp root=10.150.100.198:/srv/fai/nfsroots/vulcan-stretch:vers=3 FAI_FLAGS=verbose,sshd,createvt FAI_CONFIG_SRC=nfs://10.150.100.198/srv/fai/config/vulcan-stretch FAI_ACTION=sysinfo ... I get the infamous /tmp read-only error *although* all mounts are NFSv3: root@t-pring:~# ssh -oUserKnownHostsFile=/dev/null root@mds-eth0 The authenticity of host 'mds-eth0 (10.150.100.1)' can't be established. ECDSA key fingerprint is SHA256:dRQY3FUCjC5bCTiiXYEJxNdDVE9v2/ihKy3zc4JSkpk. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'mds-eth0,10.150.100.1' (ECDSA) to the list of known hosts. root@mds-eth0's password: Linux mds-eth0 4.9.0-5-amd64 #1 SMP Debian 4.9.65-3+deb9u2 (2018-01-04) x86_64 The programs included with the Debian GNU/Linux system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. root@mds-eth0:~# df Filesystem 1K-blocks Used Available Use% Mounted on devtmpfs 65946268 0 65946268 0% /dev tmpfs 65963204 1612 65961592 1% /run 10.150.100.198:/srv/fai/nfsroots/vulcan-stretch 622391552 497678848 124712704 80% / 10.150.100.198:/srv/fai/config/vulcan-stretch 622391552 497678848 124712704 80% /var/lib/fai/config root@mds-eth0:~# mount proc on /proc type proc (rw,nosuid,nodev,noexec,relatime) sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime) devtmpfs on /dev type devtmpfs (rw,nosuid,noexec,size=65946268k,nr_inodes=16486567,mode=755) devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000) tmpfs on /run type tmpfs (rw,nosuid,nodev,noexec,mode=755) 10.150.100.198:/srv/fai/nfsroots/vulcan-stretch on / type nfs (ro,relatime,vers=3,rsize=262144,wsize=262144,namlen=255,hard,nolock,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.150.100.198,mountvers=3,mountport=47820,mountproto=udp,local_lock=all,addr=10.150.100.198) 10.150.100.198:/srv/fai/config/vulcan-stretch on /var/lib/fai/config type nfs (ro,noatime,vers=3,rsize=262144,wsize=262144,namlen=255,acregmin=1800,acregmax=1800,acdirmin=1800,acdirmax=1800,hard,nolock,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.150.100.198,mountvers=3,mountport=47820,mountproto=udp,local_lock=all,addr=10.150.100.198) (Of course I followed the suggestions, to "catch" NFSv4 with a fake export.) Is this a new issue with recent kernels, did I miss a necessary step somewhere? Is there anything I can do to debug this? Scratching my head... S