Bug#1092123: debian-edu-config: DNS stops working on LTSP clients after unusual mksquashfs process terminates
Package: debian-edu-config
Version: 2.12.44~deb12u1
Severity: important
Dear Maintainer,
I made a default debian-edu bookworm install on single server with two
network interfaces.
Roles: main server, ltsp server, workstation
Desktop: Default/xfce
Network settings: installer defaults
Configured single 'student' user jdoe in addition to main/first user.
Proceeded to test LTSP network booting on multiple clients.
LTSP boot proceeds normally, but after login a mksquashfs process using
nearly all CPU capacity starts after about 1 minute.
Sections of the rootfs are mounted under /tmp/randomnamexx.
Client remains usable if slower, with 2G RAM usage.
A squashfs image is being created in /srv/ltsp/images/x86_64.img.tmp
This process eventually creates a 5.5GB file, /srv/ltsp/images/x86_64.img
and then terminates.
At this point, DNS name resolution stops working.
/etc/resolv.conf becomes empty (checked using 'watch /etc/resolv.conf)
Web browsing no longer works as a result, and the LDAP server can't be
accessed, so if I do a 'logout' without reboot, further login attempts fail.
The resolvconf.service is still running but can't be restarted due to
lack of privileged access.
I could not understand the purpose of creating the squashfs image on the
client.
So I decided to re-create the ltsp image on the server, with:
sudo debian-edu-ltsp-install --diskless_workstation yes
After the image is regenerated and client rebooted, the mysterious
mksquashfs process no longer runs after LTSP client logon, and DNS etc
function normally.
I am guessing there is an issue with the LTSP image creation in the original installer. Checked by reinstall from scratch, problem reappears.
As I am new to the rather complex setup of debian-edu, I can't be more specific than that, sorry.
Chris Billington
-- System Information:
Debian Release: 12.8
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)
Kernel: Linux 6.1.0-28-amd64 (SMP w/8 CPU threads; PREEMPT)
Kernel taint flags: TAINT_FIRMWARE_WORKAROUND
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB.UTF-8
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages debian-edu-config depends on:
ii adduser 3.134
ii bind9-host 1:9.18.28-1~deb12u2
ii cfengine3 3.21.0-2
ii dconf-gsettings-backend [gsettings-backen 0.40.0-4
d]
ii debconf [debconf-2.0] 1.5.82
ii debconf-utils 1.5.82
ii debian-edu-artwork 2.12.4-1~deb12u1
ii e2fsprogs 1.47.0-2
ii education-tasks 2.12.15
ii fping 5.1-1
ii gnutls-bin 3.7.9-2+deb12u3
ii iptables 1.8.9-2
ii isenkram-cli 0.51
ii ldap-utils 2.5.13+dfsg-5
ii libconfig-inifiles-perl 3.000003-2
ii libfilesys-df-perl 0.92-7+b1
ii libglib2.0-bin 2.74.6-2+deb12u4
ii libhtml-fromtext-perl 2.07-3
ii libio-socket-ssl-perl 2.081-2
ii libnet-ldap-perl 1:0.6800+dfsg-1
ii libnet-netmask-perl 2.0002-2
ii libnss3-tools 2:3.87.1-1+deb12u1
ii libpacparser1 1.3.6-1.4
ii libpam-python 1.1.0~git20220701.1d4e111-0.3+b1
ii libproxy1-plugin-kconfig 0.4.18-1.2
ii libproxy1-plugin-networkmanager 0.4.18-1.2
ii libproxy1-plugin-webkit 0.4.18-1.2
ii libsitesummary-perl 0.1.56~deb12u2
ii libterm-readkey-perl 2.38-2+b1
ii libtext-unaccent-perl 1.08-1.3+b7
ii lockfile-progs 0.1.19
ii lsb-release 12.0-1
ii media-types 10.0.0
ii net-tools 2.10-0.1
ii ng-utils 1.1-1
ii openssl 3.0.15-1~deb12u1
ii patch 2.7.6-7
ii python3 3.11.2-1+b1
ii python3-notify2 0.3-5
ii ssl-cert 1.1.2
ii swaks 20201014.0-2
ii tftp-hpa 5.2+20150808-1.4
ii uuid 1.6.2-1.5+b11
ii wget 1.21.3-1+b2
Versions of packages debian-edu-config recommends:
ii binutils 2.40-2
ii libnotify-bin 0.8.1-1
ii lsof 4.95.0-1
ii memtest86+ 6.10-4
ii resolvconf 1.91+nmu1
ii syslinux 3:6.04~git20190206.bf6db5b4+dfsg1-3+b1
debian-edu-config suggests no packages.
-- Configuration Files:
/etc/bind/db.0.168.192.in-addr.arpa. [Errno 13] Permission denied: '/etc/bind/db.0.168.192.in-addr.arpa.'
/etc/bind/db.1.168.192.in-addr.arpa. [Errno 13] Permission denied: '/etc/bind/db.1.168.192.in-addr.arpa.'
/etc/bind/db.10.in-addr.arpa. [Errno 13] Permission denied: '/etc/bind/db.10.in-addr.arpa.'
/etc/bind/db.intern [Errno 13] Permission denied: '/etc/bind/db.intern'
/etc/bind/db.subnet00.intern [Errno 13] Permission denied: '/etc/bind/db.subnet00.intern'
/etc/bind/db.subnet01.intern [Errno 13] Permission denied: '/etc/bind/db.subnet01.intern'
/etc/sssd/sssd-debian-edu.conf [Errno 13] Permission denied: '/etc/sssd/sssd-debian-edu.conf'
-- debconf information:
debian-edu-config/kdc-password-empty:
* debian-edu-config/first-user-name: chris
debian-edu-config/ldap-password-mismatch:
debian-edu-config/ldap-password-empty:
debian-edu-config/kdc-password-mismatch:
* debian-edu-config/first-user-fullname: Chris Billington
* debian-edu-config/update-hostname: false
* debian-edu-config/enable-nat: true
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