This section outlines some considerations when planning a new OpenAFS
installation.
-### Servers ###
+### Server planning ###
An OpenAFS installation requires one or more servers for file storage. These
may be physical or virtual machines, running a unix-like operating system, such
same architecture and operating system, and it is not uncommon to have a
mixture of file servers running different operating systems or versions. Each
file storage servers should have one or more unix filesystem partitions for
-data and AFS-metadata storage. The files stored in these partitions can only be
-accessed using a machine running the AFS client software.
+data and AFS-metadata storage. The files stored in these partitions are stored
+in a special format and cannot be accessed directly.
The file server machines must support IPv4 and may have multiple interfaces.
By default, OpenAFS will try to use all the non-loopback interfaces available
on a file server machine. A configuration can be used to set which addresses
-are actually reachable by clients.
-
-In addition to the file servers, OpenAFS provides a specialized lookup service
-for AFS clients and file servers, the so called AFS database servers. In a
-recommended configuration, a set of three dedicated machines, physical or
-virtual, are setup as AFS database servers. It is important to have good
-availability of the hosts running the database service, and ideally, the IP
-addresses of these hosts should be changed infrequently.
-
-OpenAFS file servers and database servers are administratively grouped into a
-collection called a 'cell'. By convention, a cell name matches an internet
-domain name registered by the organization running the AFS cell. An
-organization may have multiple cells.
-
-### Kerberos ###
+are actually reachable by clients. Changing the IP address of a file server
+requires a restart of the file service process.
+
+In addition to file servers, OpenAFS provides a specialized lookup service used
+internally by AFS clients and file servers, called the AFS database servers.
+The database server processes may be run on the same as hosts as the file
+servers, however the recommended configuration is to deploy the database
+service on a set of three dedicated machines. These hosts may be physical or
+virtual machines, running a unix-like operating system. Database servers keep
+in sync with each other by exchange of network messages, so network reliability
+between database servers is important. Each database host must support IPv4
+and must have one IPv4 address. Once deployed, it is best to avoid changing
+the IP address of an AFS database server.
+
+The AFS database service is a relatively light-weight process, however
+availability of the hosts running the database service is important to the
+reliability of the AFS service.
+
+### Kerberos requirements ###
OpenAFS uses Kerberos v5 to authenticate users and processes accessing files in
the AFS filesystem, and to authenticate administrators when running
-administrative commands. This security model avoids trusting the client machines
-for user authentication, even if a user is becomes 'root' on a client.
+AFS administrative commands. This security model avoids trusting the client
+machines for user authentication, even if a user is becomes 'root' on a client.
A Kerberos v5 realm needs to be available before setting up OpenAFS. An
existing Kerberos realm can be used or a new realm will need to be setup.
Kerberos 5 implementations such as Active Directory, MIT Kerberos V, or Heimdal
-are commonly used. For compatibility with older versions of AFS, OpenAFS
-includes a deprecated, Kerberos 4 implementation called `kaserver`. You may
-see it mentioned in various older how-to guides, however `kaserver` should not
-be used for new installations of OpenAFS.
+are commonly used. A service key will need to be created by the Kerberos
+administrator for the OpenAFS service.
+
+OpenAFS includes a deprecated, Kerberos 4 implementation called `kaserver` for
+compatibility with older versions of AFS. You may see it mentioned in various
+older documentatin, how-to guides, and mail list archives, however `kaserver`
+should not be used in new installations of OpenAFS.
### Time Synchronization ###
using `ntp` or some other synchronization mechanism. Be sure ntp is installed
and working on every machine to be used as an OpenAFS client or server.
+### DNS ###
+
+You should create a DNS A record and a PTR record for each file and database
+server. It is recommended to have the PTR record match the A record, and not
+an alias.
+
+OpenAFS clients need to locate the AFS database servers. Modern clients can use
+DNS SRV (service) records to locate the AFS database servers. You may also
+which to create DNS AFSDB records for older AFS clients, which do not have
+support for the newer AFS SRV records. You will need to create SRV records
+for the `vlserver` and the `prserver` services.
+
+The following is an example DNS bind configuration.
+
+ afsdb1 IN A 80.80.0.10
+ afsdb2 IN A 80.80.0.20
+ afsdb3 IN A 80.80.0.30
+ @ IN AFSDB 1 afsdb1
+ IN AFSDB 1 afsdb2
+ IN AFSDB 1 afsdb3
+ _afs3-vlserver._udp IN SRV 10 10 7003 afsdb1
+ _afs3-vlserver._udp IN SRV 10 10 7003 afsdb2
+ _afs3-vlserver._udp IN SRV 10 10 7003 afsdb3
+ _afs3-prserver._udp IN SRV 10 10 7002 afsdb1
+ _afs3-prserver._udp IN SRV 10 10 7002 afsdb2
+ _afs3-prserver._udp IN SRV 10 10 7002 afsdb3
+
+
+### Naming considerations ###
+
+OpenAFS servers are administratively grouped into a collection called a 'cell'.
+By convention, a cell name matches an internet domain name registered by the
+organization running the AFS cell. An organization may have multiple cells.
+
+The naming convention for kerberos realms is to use an internet domain name,
+but in uppercase. The convention for AFS cell names is to match the kerberos
+realm name, but the cell name is lower case. Extra configuration is required
+if the AFS cell name needs to be different than the kerberos realm name.
+Changing these names can be challenging, so careful consideration is needed
+when selecting the kerberos realm and AFS cell names.
-### Firewalls ###
-Todo
git://git.openafs.org / openafs-wiki.git / blobdiff