Can not log on workstation installed from PXE - issues with mounting /skole/tjener/home0

classic Classic list List threaded Threaded
4 messages Options
Reply | Threaded
Open this post in threaded view
|

Can not log on workstation installed from PXE - issues with mounting /skole/tjener/home0

TELLIER Xavier
I am in the process of evaluating the implementation of DebianEDU
within a small primary school in France to replace the existing
obsolete Linux based solution I installed some years ago.

A virtual architecture has been setup and DebianEDU successfully
installed and tested with LTSP client booting by PXE on the virtual
net. First tests wee very positivie and I'd like to take the
opportunity to thank the DebianEDU/Skoelinux teams for the quality and
integration of the product.

Next par of the tests was the installation of a workstation which lead
to the following issue :
  - A DebianEDU Stretch workstation has been installed through PXE from
    a new installed/configured DebianEDU server (version 9.8).
  - Installation went fine w/o reported errors.
  - This new workstation has been declared in LDAP with :
    sitesummary2ldapdhcp -a -i ether-08:00:27:53:dd:76 -t workstations
  - Configuration has been finalised by adding wokstation-hosts,
    shutdown-at-mignight-hosts, fsautoresize-hosts wihtin NIS Netgroup.
  - Logging into the workstation via LDM with for any user declared in
    GOsa2 fails : LDM greeter disappear for a short period and reappear
  - Logging via one of the console (F1, F2, ...) is granted but warning
    appear : 'No directory, logging with HOME=/'
  - Installation checking with command 'debian-edu-test-install' lead
    to : 'error: ./automount: unable to cd
    into /skole/tjener/home0/' (complete log of the command is
    available).

The LDM logging error seems to be related to the unavailability of the
home directory that should be auto-mounted via NFS. I have been
checking in the LDAP database : the workstation is indeed declared
into the NIS group /no/skolelinux/skole/netgroup/workstation-hosts
(nisNetgroupTriple : (auto-mac-08-00-27-53-dd-76,,)
(auto-mac-08-00-27-53-dd-76.intern,,) ). I do not master autofs mount
via LDAP and failed to find the root cause of the problem.

I would be very grateful if guidance could be suggested to
understand and sort out the problem.

Best regards,

xavier TELLIER

Reply | Threaded
Open this post in threaded view
|

Re: Can not log on workstation installed from PXE - issues with mounting /skole/tjener/home0

Wolfgang Schweer-3
Hi Xavier,

On Fri, Mar 29, 2019 at 08:14:21AM +0100, TELLIER Xavier wrote:
> I am in the process of evaluating the implementation of DebianEDU
> within a small primary school in France to replace the existing
> obsolete Linux based solution I installed some years ago.

Thanks for trying Debian Edu and for your detailed report.
 
> Next par of the tests was the installation of a workstation which lead
> to the following issue :
>   - A DebianEDU Stretch workstation has been installed through PXE from
>     a new installed/configured DebianEDU server (version 9.8).
>   - Installation went fine w/o reported errors.
>   - This new workstation has been declared in LDAP with :
>     sitesummary2ldapdhcp -a -i ether-08:00:27:53:dd:76 -t workstations
>   - Configuration has been finalised by adding wokstation-hosts,
>     shutdown-at-mignight-hosts, fsautoresize-hosts wihtin NIS Netgroup.

Good, the steps are just like they should be.

>   - Logging into the workstation via LDM with for any user declared in
>     GOsa2 fails : LDM greeter disappear for a short period and reappear
>   - Logging via one of the console (F1, F2, ...) is granted but warning
>     appear : 'No directory, logging with HOME=/'

I don't have a Stretch test environment at hand. This same problem
showed up for Jessie. It had been a problem with nscd (name service
cache daemon) back then which should have gone away for Stretch.

Anyway, please run 'nscd -i netgroup' on the main server to invalidate
the related cache and see if it helps.

As a last resort you could disable netgroup caching completely running
'debian-edu-nscd-netgroup-cache disable' on the main server. (This
workaround for Jessie should not be needed for Stretch; netgroup caching
can be enabled again running 'debian-edu-nscd-netgroup-cache enable'.)

----

You could also try Debian Edu Buster. It would allow you to set up a
system tailored for a primary school (install the meta-package
'education-primaryschool' after a basic install). For details see:
https://wiki.debian.org/DebianEdu/Status/Buster
and
https://wiki.debian.org/DebianEdu/Documentation/Buster/Installation#Modular_installation

Wolfgang

signature.asc (981 bytes) Download Attachment
Reply | Threaded
Open this post in threaded view
|

Re: Re: Can not log on workstation installed from PXE - issues with mounting /skole/tjener/home0

TIRONNEAU Sylvie
Hi Wolfgang,

Thanks for the reply ; I did not thought about name service caching shadowing the netgroup update (I used sssd in the past, not nscd). Invalidating the cache did indeed help though I had to restart nscd (service nscd restart) prior to correct execution (nscd -i netgroup was otherwise hanging).

It is not clear why the service had to be restarted ; I have investigated /var/syslog and found an error reported by nscd (sorry, french based ; translation follows):
  Jan 21 06:36:39 tjener nscd: 788 surveillance basée sur inotify désactivée pour fichier `/etc/netgroup': Aucun fichier ou dossier de ce type
  Jan 21 06:36:39 tjener nscd: 788 stat en échec pour fichier `/etc/netgroup'; nouvel essai plus tard: Aucun fichier ou dossier de ce type

  Jan 21 06:36:39 tjener nscd: 788 surveillance based on inotify deactivated for the file '/etc/netgroup': No files or folders of this type
  Jan 21 06:36:39 tjener nscd: 788 stat defeated for file `/etc/netgroup'; new tentative later: No file or folder of this type

Here follows an extract from /var/syslog just after restarting the service which shows that the error remains after restart:
  Mar 29 19:38:37 tjener systemd[1]: Stopping Name Service Cache Daemon...
  Mar 29 19:38:37 tjener systemd[1]: Stopped Name Service Cache Daemon.
  Mar 29 19:38:37 tjener systemd[1]: Starting Name Service Cache Daemon...
  Mar 29 19:38:37 tjener nscd: 6016 fichier de surveillance `/etc/passwd` (1)
  Mar 29 19:38:37 tjener nscd: 6016 répertoire de surveillance `/etc` (2)
  Mar 29 19:38:37 tjener nscd: 6016 fichier de surveillance `/etc/group` (3)
  Mar 29 19:38:37 tjener nscd: 6016 répertoire de surveillance `/etc` (2)
  Mar 29 19:38:37 tjener nscd: 6016 fichier de surveillance `/etc/hosts` (4)
  Mar 29 19:38:37 tjener nscd: 6016 répertoire de surveillance `/etc` (2)
  Mar 29 19:38:37 tjener nscd: 6016 fichier de surveillance `/etc/resolv.conf` (5)
  Mar 29 19:38:37 tjener nscd: 6016 répertoire de surveillance `/etc` (2)
  Mar 29 19:38:37 tjener nscd: 6016 fichier de surveillance `/etc/services` (6)
  Mar 29 19:38:37 tjener nscd: 6016 répertoire de surveillance `/etc` (2)
  Mar 29 19:38:37 tjener nscd: 6016 surveillance basée sur inotify désactivée pour fichier `/etc/netgroup': Aucun fichier ou dossier de ce type
  Mar 29 19:38:37 tjener nscd: 6016 stat en échec pour fichier `/etc/netgroup'; nouvel essai plus tard: Aucun fichier ou dossier de ce type
  Mar 29 19:38:37 tjener systemd[1]: Started Name Service Cache Daemon.
  Mar 29 19:38:41 tjener nscd: 6016 surveillance basée sur inotify désactivée pour fichier `/etc/netgroup': Aucun fichier ou dossier de ce type
  Mar 29 19:38:56 tjener nscd: 6016 recherche fichier surveillé `/etc/netgroup': Aucun fichier

I checked, /etc/netgroup does not exist (whihc may be understandable as the information is contained wihtin LDAP). I have not been able to evidence if this could be the root for the misbehavior. I'll try to install another virtual workstation and declare it on LDAP netgroup. I guess I should also document myself a little more on nscd.

I'll give a look to Buster.

Thanks again for the guidance ; I really appreciate the help.

Best regards,

Xavier TELLIER.

Reply | Threaded
Open this post in threaded view
|

Re: Re: Can not log on workstation installed from PXE - issues with mounting /skole/tjener/home0

Wolfgang Schweer-3
Hi Xavier,

On Fri, Mar 29, 2019 at 08:16:43PM +0100, Xavier TELLIER wrote:

> Thanks for the reply ; I did not thought about name service caching
> shadowing the netgroup update (I used sssd in the past, not nscd).

Yes, sssd would be a better choice...

> Invalidating the cache did indeed help though I had to restart nscd
> (service nscd restart) prior to correct execution (nscd -i netgroup
> was otherwise hanging).

This seems to have been fixed in the meantime, on Buster it works w/o
problems.

Obviously the 'hanging' problem has been a known issue also elsewhere,
see: https://bugzilla.redhat.com/show_bug.cgi?id=1277672

> I checked, /etc/netgroup does not exist (whihc may be understandable
> as the information is contained wihtin LDAP). I have not been able to
> evidence if this could be the root for the misbehavior.

I guess the settings in /etc/nsswitch.conf should care for this (LDAP).
 
> I'll give a look to Buster.

Please note that the fixed busybox package will need another 5 days to
migrate to buster, so LTSP clients won't start; see (first item):
https://wiki.debian.org/DebianEdu/Status/Buster#Fixed_.2B-_done_.28related_packages_migrated_to_buster_or_unstable.29

Good luck,
Wolfgang

signature.asc (981 bytes) Download Attachment