1 <?xml version="1.0" encoding="UTF-8"?>
2 <refentry id="CellServDB5">
4 <refentrytitle>CellServDB</refentrytitle>
5 <manvolnum>5</manvolnum>
8 <refname>CellServDB</refname>
9 <refpurpose>Lists the database server machines in AFS cells</refpurpose>
12 <title>Description</title>
13 <para>There are two versions of the <replaceable>CellServDB</replaceable> file, both of which have the
14 same format. One version is used by an AFS client and lists all of the
15 database server machines in the local cell and any foreign cell that is to
16 be accessible from the local client machine. The other version is used on
17 servers and lists only the database servers in the local cell.</para>
20 <title>Client CellServDB</title>
21 <para>The client version of the CellServDB file lists the database server
22 machines in the local cell and any foreign cell that is to be accessible
23 from the local client machine. Database server machines run the
24 Authentication Server, Backup Server, Protection Server, and Volume
25 Location (VL) Server (the <emphasis role="bold">kaserver</emphasis>, <emphasis role="bold">buserver</emphasis>, <emphasis role="bold">ptserver</emphasis>, and
26 <emphasis role="bold">vlserver</emphasis>) processes, which maintain the cell's administrative AFS
29 <para>The Cache Manager and other processes running on a client machine use the
30 list of a cell's database server machines when performing several common
31 functions, including:</para>
35 <para>Fetching files. The Cache Manager contacts the VL Server to learn
36 the location of the volume containing a requested file or directory.</para>
40 <para>Authenticating users. Client-side authentication programs (such as an
41 AFS-modified login utility or the <emphasis role="bold">klog</emphasis> command interpreter) contact the
42 Authentication Server to obtain a server ticket, which the AFS server
43 processes accept as proof that the user is authenticated.</para>
47 <para>Creating protection groups. The <emphasis role="bold">pts</emphasis> command interpreter contacts the
48 Protection Server when users create protection groups or request
49 information from the Protection Database.</para>
53 <para>The Cache Manager reads the CellServDB file into kernel memory as it
54 initializes, and not again until the machine next reboots. To enable users
55 on the local machine to continue accessing the cell correctly, update the
56 file whenever a database server machine is added to or removed from a
57 cell. To update the kernel-resident list of database server machines
58 without rebooting, use the <emphasis role="bold">fs newcell</emphasis> command.</para>
60 <para>The <replaceable>CellServDB</replaceable> file is in ASCII format and must reside in the
61 <replaceable>/usr/vice/etc</replaceable> directory on each AFS client machine. Use a text editor
62 to create and maintain it.</para>
64 <para>The client version of the <replaceable>CellServDB</replaceable> file is distinct from the server
65 version, which resides in the <replaceable>/usr/afs/etc</replaceable> directory on each AFS server
66 machine. The client version lists the database server machines in every
67 AFS cell that the cell administrator wants the machine's users to be able
68 to access, whereas the server version lists only the local cell's database
69 server machines.</para>
73 <title>Server CellServDB</title>
74 <para>The server version of the <replaceable>CellServDB</replaceable> file lists the local cell's
75 database server machines. These machines run the Authentication Server,
76 Backup Server, Protection Server, and Volume Location (VL) Server (the
77 <emphasis role="bold">kaserver</emphasis>, <emphasis role="bold">buserver</emphasis>, <emphasis role="bold">ptserver</emphasis>, and <emphasis role="bold">vlserver</emphasis>) processes, which
78 maintain the cell's administrative AFS databases. The initial version of
79 the file is created with the <emphasis role="bold">bos setcellname</emphasis> command during the
80 installation of the cell's server machine, which is automatically recorded
81 as the cell's first database server machine. When adding or removing
82 database server machines, be sure to update this file appropriately. It
83 must reside in the <replaceable>/usr/afs/etc</replaceable> directory on each AFS server machine.</para>
85 <para>The database server processes consult the <replaceable>CellServDB</replaceable> file to learn
86 about their peers, with which they must maintain constant connections in
87 order to coordinate replication of changes across the multiple copies of
88 each database. The other AFS server processes consult the file to learn
89 which machines to contact for information from the databases when they
92 <para>Although the server <replaceable>CellServDB</replaceable> file is in ASCII format, do not use a
93 text editor to alter it. Instead always use the appropriate commands from
94 the <emphasis role="bold">bos</emphasis> command suite:</para>
98 <para>The <emphasis role="bold">bos addhost</emphasis> command to add a machine to the file.</para>
102 <para>The <emphasis role="bold">bos listhosts</emphasis> command to display the list of machines from the
107 <para>The <emphasis role="bold">bos removehost</emphasis> command to remove a machine from the file.</para>
111 <para>In cells that use the Update Server to distribute the contents of the
112 <replaceable>/usr/afs/etc</replaceable> directory, it is customary to edit only the copy of the
113 file stored on the system control machine. Otherwise, edit the file on
114 each server machine individually. For instructions on adding and removing
115 database server machine, see the <emphasis>IBM AFS Quick Beginnings</emphasis> chapter on
116 installing additional server machines.</para>
120 <title>CellServDB Format</title>
121 <para>Both <replaceable>CellServDB</replaceable> files have the same format:</para>
125 <para>The first line begins at the left margin with the greater-than character
126 (<computeroutput>></computeroutput>), followed immediately by the cell's name without an intervening
127 space. Optionally, a comment can follow any number of spaces and a number
128 sign (<computeroutput>#</computeroutput>), perhaps to identify the organization associated with the
133 <para>Each subsequent line in the entry identifies one of the cell's database
134 server machines, with the indicated information in order:</para>
138 <para>The database server machine's IP address in dotted-decimal format.</para>
142 <para>One or more spaces.</para>
146 <para>A number sign (#), followed by the machine's fully qualified hostname
147 without an intervening space. This number sign does not indicate that the
148 hostname is a comment. It is a required field.</para>
154 <para>No extra blank lines or newline characters are allowed in the file, even
155 after the last entry. Their presence can prevent the Cache Manager from
156 reading the file into kernel memory, resulting in an error message.</para>
158 <para>grand.central.org maintains a list of the database server machines in all
159 cells that have registered themselves as receptive to access from foreign
160 cells. When a cell's administrators change its database server machines,
161 it is customary to register the change with grand.central.org for
162 inclusion in this file. The file conforms to the required <replaceable>CellServDB</replaceable>
163 format, and so is a suitable basis for the <replaceable>CellServDB</replaceable> file on a client
164 machine. You can download this file from http://grand.central.org/.</para>
169 <title>Examples</title>
170 <para>The following example shows entries for two cells in a client
171 <replaceable>CellServDB</replaceable> file and illustrates the required format.</para>
174 &gt;abc.com # ABC Corporation
175 192.12.105.2 #db1.abc.com
176 192.12.105.3 #db2.abc.com
177 192.12.107.3 #db3.abc.com
178 &gt;test.abc.com # ABC Corporation Test Cell
179 192.12.108.57 #testdb1.abc.com
180 192.12.108.55 #testdb2.abc.com
185 <title>See Also</title>
186 <para><link linkend="bos_addhost8">bos_addhost(8)</link>,
187 <link linkend="bos_listhosts8">bos_listhosts(8)</link>,
188 <link linkend="bos_removehost8">bos_removehost(8)</link>,
189 <link linkend="bos_setcellname8">bos_setcellname(8)</link>,
190 <link linkend="buserver8">buserver(8)</link>,
191 <link linkend="fs_newcell1">fs_newcell(1)</link>,
192 <link linkend="kaserver8">kaserver(8)</link>,
193 <link linkend="klog1">klog(1)</link>,
194 <link linkend="ptserver8">ptserver(8)</link>,
195 <link linkend="vlserver8">vlserver(8)</link>,
196 <link linkend="upclient8">upclient(8)</link>,
197 <link linkend="upserver8">upserver(8)</link></para>
199 <para><emphasis>IBM AFS Quick Beginnings</emphasis></para>
203 <title>Copyright</title>
204 <para>IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.</para>
206 <para>This documentation is covered by the IBM Public License Version 1.0. It was
207 converted from HTML to POD by software written by Chas Williams and Russ
208 Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.</para>