On the computer's host

LXC

TODO: what is the procedure for renaming an LXC? http://www.bonusbits.com/wiki/HowTo:Rename_LXC_Container

Xen

TODO: what is the procedure for renaming a Dom0 (nothing special?) and a DomU (at least the DomU's config file, log and autostart link on the Dom0 include the DomU's FQDN).

On the computer

All distributions

Cyrus

TBC

LVM

TODO: develop procedure for renaming the volume group and document here (when / is on LVM as ours normally are, this may require rebuilding the initial RAM disk, re-configuring the boot manager, editing fstab ...).  Maybe useful links: https://we.riseup.net/debian/renaming-a-lvm-root-volume-group, https://bugzilla.redhat.com/show_bug.cgi?id=230190#c17 (RedHat),

Name resolution

/etc/hosts  If the name change includes a domain name change and the old domain name appears in /etc/hosts for the computer then it must be changed.

/etc/resolv.conf{,.head,.tail}  If all these conditions are met ...

1. The name change includes a domain name change.
2. /etc/resolv.conf is either a local file or includes a local head or tail file.
3. The local file(s) include a domain line.

... then any domain line(s) in /etc/resolv.conf{,.head,.tail} may need adjusting.

OpenLDAP

TBC.  May involve re-generating certificates.

OpenVPN

Remove any OpenVPN client configuration for the old name: OpenVPN#Ontheclient

The next step is most commonly done on the client but may need to be done partly on the primary OpenVPN server, details in the linked section.

Set up the OpenVPN client under the new name: OpenVPN#Per-clientconfiguration%28serverandclient%29

Postfix

Do not restart or reload postfix until all files have been updated.

Update by editing:

• /etc/aliases  If it is changed, run the newalises command.
• /etc/mailname
• /etc/postfix/header_checks  If the file doesn't exist, create it using the procedure at http://wiki.bluelightav.org/x/PAIW 
• /etc/postfix/generic  If it is changed, run the postmap command on it, in the /etc/postfix directory.

Update /etc/postfix/main.cf by (replacing <hostname> and <domain>):

• postconf -e myhostname=<hostname>

• postconf -e mydestination=<hostname>,localhost.<domain>,localhost

Restart postfix:

/etc/init.d/postfix reload

In case there is undelivered mail from the old hostname, if not required it can be deleted using  postsuper -d ALL

Debian

Reference: Debian WIKI page on changing hostname.

Ubuntu

Change the hostname

• Edit /etc/hostname
• Edit /etc/hosts
• service hostname restart

On other computers

Backup systems

Backed up on bafi

If the computer is backed up on bafi, either by push from the computer or pull from bafi:

1. Find which file system it is backed up to and adjust directory name(s) accordingly.
2. Adjust directories and symlinks under /var/backup.

DHCP servers

LTSP

Not tested (may all be done by the commands above): if running or using any of avahi, CUPS, ejabberd, Exim, /etc/motd, OpenSSH server, ssmtp or sysklogd then read the  Debian WIKI page on changing hostname.

DNS servers

On master DNS servers which have record(s) for the old name, change the forward zone file and any reverse zone file.  The DNS servers to consider are:

• dns2.bluelightav.org for public network addresses.
• openvpn.bluelightav.org for BL OpenVPN network addresses.
• bafi for Town Hall addresses.

LDAP server

TODO: when this section is understood, move it or not.  It is not clear whether it applies on the computer being renamed (in which case it should be above) or on another computer (in which case it is correctly here).

Change the LDAP client's uri

• edit /etc/ldap.conf
• replace the uri=service.av to the appropriate hostname. Note: if the uri=ldapi:/// or anything else of the kind, leave it
• service slapd restart