NAME

       ThisCell - Defines the local cell name

DESCRIPTION

       The ThisCell file defines the local cell name.  There are two versions of this file, one for a AFS client
       and one for an AFS server.

   Client ThisCell
       The client version of the ThisCell file defines the complete Internet domain-style name (for example,
       "example.com") of the cell to which the local client machine belongs. It must reside in the /etc/openafs
       directory on every AFS client machine. To change a client machine's cell membership, edit the file and
       reboot the machine.

       The file is in ASCII format and contains a character string on a single line. The OpenAFS Quick Start
       Guide instructs the administrator to create it during the installation of each client machine.

       The client machine's cell membership determines three defaults important to its functioning:

       •   The cell in which the machine's users authenticate by default.  The effect is two-fold:

           •   The  AFS-modified  login  utilities  and  the  klog command interpreter contact an Authentication
               Server in the cell named in the  ThisCell  file  (unless  -cell  argument  to  the  klog  command
               specifies an alternate cell).

           •   The  command  interpreters  combine  the  cell  name  with  the  password that the user provides,
               generating an encryption key from the combination. For authentication to succeed, both  the  cell
               name  and  password  must match the ones used to generate the user's encryption key stored in the
               Authentication Database.

       •   The cell the Cache Manager considers its local, or home, cell. By default, the Cache  Manager  allows
           programs  that  reside  in its home cell to run with setuid permission, but not programs from foreign
           cells. For more details, see the fs getcellstatus and fs setcell reference pages.

       •   Which AFS server processes the local AFS command interpreters contact  by  default  as  they  execute
           commands issued on the machine.

       The  client  version  of  the  ThisCell  file  is  distinct from the server version, which resides in the
       /etc/openafs/server directory on each AFS server machine. If a server machine also runs as a  client,  it
       is acceptable for the server and client versions of the file on the same machine to name different cells.
       However, the behavior that results from this configuration can be more confusing than useful.

   Server ThisCell
       The  server  version  of  the ThisCell file defines the complete Internet domain-style name (for example,
       "example.com") of the cell to which the server machine belongs. It must reside in the /etc/openafs/server
       directory on every AFS server machine.

       The file is in ASCII format and contains a character string on a single line. The initial version of  the
       file  is created with the bos setcellname command during the installation of the cell's first file server
       machine, and the OpenAFS Quick Start Guide includes instructions for copying it over to additional server
       machine during their installation.

       The only reason to edit the file is as part of changing the cell's name, which  is  strongly  discouraged
       because  of  the  large  number  of configuration changes involved. In particular, changing the cell name
       requires rebuilding the entire Authentication Database, because the Authentication  Server  combines  the
       cell  name  it finds in this file with each user and server password and converts the combination into an
       encryption key before recording it in the Database.

SEE ALSO

       bos_setcellname(8), fs_getcellstatus(1), fs_setcell(1)

COPYRIGHT

       IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.

       This documentation is covered by the IBM Public License Version 1.0.  It was converted from HTML  to  POD
       by  software  written  by  Chas  Williams  and Russ Allbery, based on work by Alf Wachsmann and Elizabeth
       Cassell.

OpenAFS                                            2025-05-19                                        THISCELL(5)