Petter Reinholdtsen

On larger sites, it is useful to use a dedicated storage server for storing user home directories and data. The design for handling this in Debian Edu / Skolelinux, is to update the automount rules in LDAP and let the automount daemon on the clients take care of the rest. I was reminded about the need to document this better when one of the customers of Skolelinux Drift AS, where I am on the board of directors, asked about how to do this. The steps to get this working are the following:

1. Add new storage server in DNS. I use nas-server.intern as the example host here.
2. Add automoun LDAP information about this server in LDAP, to allow all clients to automatically mount it on reqeust.
3. Add the relevant entries in tjener.intern:/etc/fstab, because tjener.intern do not use automount to avoid mounting loops.

DNS entries are added in GOsa², and not described here. Follow the instructions in the manual (Machine Management with GOsa² in section Getting started).

Ensure that the NFS export points on the server are exported to the relevant subnets or machines:

root@tjener:~# showmount -e nas-server
Export list for nas-server:
/storage         10.0.0.0/8
root@tjener:~#

Here everything on the backbone network is granted access to the /storage export. With NFSv3 it is slightly better to limit it to netgroup membership or single IP addresses to have some limits on the NFS access.

The next step is to update LDAP. This can not be done using GOsa², because it lack a module for automount. Instead, use ldapvi and add the required LDAP objects using an editor.

ldapvi --ldap-conf -ZD '(cn=admin)' -b ou=automount,dc=skole,dc=skolelinux,dc=no

When the editor show up, add the following LDAP objects at the bottom of the document. The "/&" part in the last LDAP object is a wild card matching everything the nas-server exports, removing the need to list individual mount points in LDAP.

add cn=nas-server,ou=auto.skole,ou=automount,dc=skole,dc=skolelinux,dc=no
objectClass: automount
cn: nas-server
automountInformation: -fstype=autofs --timeout=60 ldap:ou=auto.nas-server,ou=automount,dc=skole,dc=skolelinux,dc=no

add ou=auto.nas-server,ou=automount,dc=skole,dc=skolelinux,dc=no
objectClass: top
objectClass: automountMap
ou: auto.nas-server

add cn=/,ou=auto.nas-server,ou=automount,dc=skole,dc=skolelinux,dc=no
objectClass: automount
cn: /
automountInformation: -fstype=nfs,tcp,rsize=32768,wsize=32768,rw,intr,hard,nodev,nosuid,noatime nas-server.intern:/&

The last step to remember is to mount the relevant mount points in tjener.intern by adding them to /etc/fstab, creating the mount directories using mkdir and running "mount -a" to mount them.

When this is done, your users should be able to access the files on the storage server directly by just visiting the /tjener/nas-server/storage/ directory using any application on any workstation, LTSP client or LTSP server.