KAFS-CLIENT.CONF(5)

📦
version 0.9 · 6 versions
, in fedora 43, fedora 44

KAFS-CLIENT.CONF(5) 💅

okay bestie, welcome to the kafs-client manual, section 5. we're talking about /etc/kafs/client.conf — the kAFS filesystem configuration file. yes, the whole thing. grab a strawberry 🍓, we're going in.

✨ NAME ✨

/etc/kafs/client.conf — kAFS filesystem configuration. that's it, that's the name, she's simple and she's iconic 👑

🦋 DESCRIPTION 🦋

so like, configuration info for the in-kernel kAFS filesystem can be provided in the /etc/kafs/ directory. and it may include the following:

  • a list of cells to be preconfigured
  • fallback addresses for each cell
  • the name of the default cell (the @cell substitution)
  • a list of strings for (the @sys substitution)

when the afs.mount service is started by systemd(1), a configuration service (kafs-config.service) runs first and loads the configuration into the kernel from the client.conf file. this contains directives to include other things, such as the contents of the client.d/ directory and the generic public cell database. it's giving "prep work before the main event" 💖

once the afs.mount service is started (or if an AFS volume is manually mounted), if a mountpoint is triggered, the kernel will upcall by means of request-key(8) to look up addresses for the Volume Location servers for the named cell. this will also parse the configuration. no cap, the kernel is out here doing side quests 🌸

🎀 CONFIGURATION FILE FORMAT 🎀

the file format is based on the MIT Kerberos configuration file format. cute, borrowing from a classic. there are a couple of general directives:

  • include /path/to/file — this includes the contents of the named file in the parse at this point.
  • includedir /path/to/dir/ — this includes the files in the named directory in the parse at this point. files that have names beginning with . or ending with ~ are ignored. (they're in their private era, we leave them alone 🙈)

leading and trailing whitespace on a line is ignored. any line otherwise beginning with a # character is considered a comment and ignored.

any line that contains a label bounded by square brackets, e.g. [cells], by itself on that line denotes a switch to the section specified by that label.

configuration data is specified within a named section as a series of key = value pairs, where a value may be one of nothing, an unquoted string, a quoted string or a braced lists containing further key=value pairs. whitespace either side of the = symbol is ignored.

for example:

[cells]
rivendell.example.com = {
  description = "Last Homely Cell"
  use_dns = yes
  servers = {
          elrond.rivendell.example.com = {
                  address = 192.0.2.23
          }
  }
}

if two or more consecutive clauses specify values for the same key sequence (so cells:rivendell.example.com:use_dns, for example), then they are merged together to form a single list. if a single value is expected for a configuration item, the last element in the list is taken. last one standing, periodt 💅

to prevent overriding by subsequent conflicting configuration, an asterisk can be placed after the closing brace in a braced list to indicate that that list is closed, for example:

[cells]
rivendell.example.com = {
  description = "Foo"
  use_dns = no
}*

strings that are intepreted as boolean values are classed as false if they match one of: 0, f, false, n, no, or off. boolean values are classed as true if they match one off: 1, t, true, y, yes, or on. boolean matches are case-independent. the vibe check is case-insensitive besties ✨

💜 GENERAL SETTINGS 💜

the first section contains general system-level settings shared between all utilities and the kernel. this is denoted by the section label [defaults].

the system settings that may be changed are configured in this section with the following key-value pairs:

  • thiscell = <cellname> — this sets the name of the local cell. this will be used to configure the @cell path substitution and will also supply the default cellname for aklog-kafs(1).
  • sysname = [<systype>]* — this specifies a (potentially empty) list of strings which the kernel should attempt to substitute in turn for @sys at the end of a filename until a match is found.

👑 CELL DEFINITIONS 👑

the second section contains a list of preconfigured cells, to be used in preloading the cell list in /afs and also to provide fallback or override address data for locating Volume Location servers. this is denoted by the section label [cells].

within the cell list, each cell is declared with a key=value pair, where the key is the name of the cell and the value is a braced list indicating the details, e.g.:

[cells]
rivendell.example.com = {
  ...
}

a cell definition may contain any number of key=value pairs. the keys that are taken note of are:

  • description = <string> — this is a text description for the cell.
  • show_cell = <boolean> — whether a cell should be shown in /afs.
  • use_dns = <boolean> — whether address look ups for a cell may use the DNS.
  • kerberos_realm = <string> — the name of the Kerberos realm to use for a cell by default.
  • servers = { ... } — a list of servers for the cell, where each element in the list is a key=value pair, where the key is the name of a server and the value is a braced section of the details for that server.

the elements in the list of server details attached to each server can comprise the following keys:

  • type = vlserver — the server is an AFS Volume Location server. this is the default.
  • type = ptserver — the server is an AFS Protection server.
  • address = [<protocol>/]<address>[:<port>] — specify a single address for a server. the address is required and can be a single IPv4 or a single IPv6 address, and may be brackets with square brackets (to avoid confusion with the port number, if specified). the protocol is optional; currently only udp is supported. the port is also optional and may be specified to change the UDP port from the default for the server type.

🌈 EXAMPLE 🌈

[defaults]
thiscell = rivendell.example.com
sysname = fedora28_x86 amd64_linux

[cells]
corp.example.com = {
  description = "Valinor Corporation cell"
  use_dns = yes
  servers = {
          manwe.corp.example.com = {
                  address = 2001:db8:123::13
                  address = 203.0.113.19
          }
          ulmo.corp.example.com = {
                  address = [2001:db8:123::750c:1234]:6666
                  address = 203.0.113.3:6666
          }
          aule.corp.example.com = {
                  address = udp/[2001:db8:123::abcd:9090]
                  address = udp/203.0.113.189
          }
          namo.corp.example.com = {
                  type = ptserver
                  address = 2001:db8:123::8888
                  address = 203.0.113.88
          }
  }
}

rivendell.example.com = {
  description = "Last Homely Cell"
  servers = {
          elrond.rivendell.example.com = {
                  address = 192.0.2.23
          }
          arwen.rivendell.example.com = {
                  address = 192.0.2.75
          }
  }
}

🌸 SEE ALSO 🌸

kafs(7), kafs-check-config(8), kafs-preload(8), systemd(1)

Copyright (C) 2019 Red Hat, Inc. All Rights Reserved.

Written by David Howells (dhowells@redhat.com)

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

and that's the whole page bestie, you ate it up 💅✨ this was kafs-client version 0.9, dated 2026-08-27, and it lives under the KAFS-CLIENT.CONF(5) manual. go configure something iconic 🦋💖

📦 where this page comes from