Product Notes for All System Types

• Limit on number of file server machine interfaces

  AFS supports up to 15 addresses on a multihomed file server machine. If more interfaces are configured with the operating system, AFS uses only the first 15.

• Limit on number of client machine interfaces

  AFS supports up to 32 addresses on a multihomed client machine. Do not configure more interfaces.

• Limit on number of AFS server partitions

  AFS supports up to 256 server (/vicep) partitions on a file server machine. This corresponds to directory names /vicepa through /vicepz and /vicepaa through /vicepiv.

• Limit on number of file server machines

  The VLDB can store up to 255 server entries, each representing one file server machine (single- or multihomed). This effectively determines the maximum number of file server machines in the cell. To make room in the VLDB for new server entries, use the vos changeaddr command's -remove argument to remove the entries for decommissioned file server machines.

• Limit on file size

  AFS supports a maximum file size of 2 GB.

• Limit on volume and partition size

  AFS supports a maximum volume size of 8 GB. In AFS version 3.5 and earlier, the limit is 2 GB. There is no limit on partition size other than the one imposed by the operating system.

• Limit on cache size

  AFS supports a maximum disk cache size of 1 GB. In AFS version 3.1 and earlier, the limit is 700 MB.

• Limit on number of File Server threads

  The File Server (fileserver process) can use up to 128 threads, unless the operating system imposes a lower limit. Testing for the AFS 3.6 GA release indicates that HP-UX sometimes imposes a lower limit, depending on the resources available on a machine. See Product Notes for HP-UX Systems below. The File Server always reserves seven threads for special uses, so the maximum effective value for the fileserver command's -p argument is seven less than the actual limit. On most systems, the effective maximum is therefore 121.

• Limit on number of volume site definitions

  The VLDB entry for a volume can accommodate a maximum of 13 site definitions. The site housing the read/write and backup versions of the volume counts as one site, and each read-only site counts as an additional site (even the read-only site defined on the same partition as the read/write site counts as a separate site).

• No support for VxFS as server or cache partition

  AFS does not support use of the VxFS file system as either a client cache partition or server (/vicep) partition. It is acceptable to use both VxFS and AFS on the same machine, but the cache partition and all AFS server partitions must use a supported file system type such as UFS. See the following sections of this document for similar restrictions affecting particular operating systems.

• Run same version of a server process on all server machines

  For predictable performance, run the same version of an AFS server process on all server machines in a cell. For example, if you upgrade the Volume Location Server process on a database server machine to OpenAFS 1.0.4, you must upgrade it on all of them. The upgrade instructions in Upgrading Server and Client Machines to AFS 3.6 have you upgrade the binaries for all server processes on all machines to the same version, and in general that is the best policy. Unless otherwise noted, it is acceptable to run different build levels of a major version on different machines (for example, AFS 3.5 build 3.0 on one machine and AFS 3.5 build 3.11 on another).

• Single edition of AFS for all countries

  There is a single edition of OpenAFS 3.6 for both North American and international users. For details, see the Summary of New Features.

• TSM is the supported XBSA server

  The AFS 3.6 (on which OpenAFS is based) Backup System can communicate with one XBSA server, the Tivoli Storage Manager (TSM). There are several requirements and limitations associated with its use, as detailed in the section entitiled Product Notes for Use of TSM.

• Use Netscape 4.0 or higher

  If using a Netscape browser to read the HTML version of an AFS document, use version 4.0 or higher. Some fonts used in the documents possibly do not display properly in earlier versions.

• Set the Acrobat Reader environment to English

  The user interface to the Adobe Acrobat Reader program for displaying PDF files works correctly only when the program's language environment is set to English. Users in non-English language locales probably need to adjust the language setting. See Accessing the AFS Binary Distribution and Documentation.

• No support for IPv6

  AFS does not support version 6 of the Internet Protocol (IPv6). You must continue to specify the IPv4 protocol names udp and tcp in the entries for AFS-modified services in the inetd configuration file, rather than the IPv6 names upd6 and tcp6. If you use the IPv6 version, the AFS-modified inetd daemon cannot locate the service and does not open the service's port. The inetd configuration file included with some operating system revisions possibly specifies IPv6 protocols by default. You must modify or replace the file in order to use the AFS-modified version of remote services.

• Limit on directory size when element names are long

  If the name of every file system element (file, link, or subdirectory) in a directory is 16 characters or more, then when there are about 31,700 elements it becomes impossible to create any more elements with long names. It is still possible to create elements with names shorter than 16 characters. This limitation is due to the way AFS implements directories. For a more detailed explanation, contact your AFS product support representative.

• Setting setuid or setgid bit on file fails silently

  Only members of the system:administrators group can turn on the setuid or setgid mode bit on an AFS file or directory. However, AFS generates an error message only when a regular user attempts to set the bit on a directory. Attempts on a file fail silently.

• The add instruction in the uss bulk input file does not work as documented

  The documentation specifies the following syntax for creating an authentication-only account (entries in the Authentication and Protection Databases only) by using an add instruction in the uss bulk template file:

  add username[:]

  However, you must in fact follow the username value with two colons for the uss bulk command to create the account:

  add username::

• Running the backup savedb command blocks other Backup System operations

  The Backup Server locks the Backup Database as it performs the backup savedb command, which can take a long time. Because other backup operations cannot access the database during this time, they appear to hang. Avoid running other backup operations after issuing the backup savedb command. Actually, this limitation applies to any operation that locks the Backup Database for a significant amount of time, but most other operations do not. In any case, running the backup savedb command is appropriate only in the rare case when the Backup Database is corrupted, so this limitation usually does not have a significant impact.

• NFS/AFS Translator sometimes performs poorly under heavy load

  The NFS/AFS Translator does not always perform well under heavy load. Sometimes the translator machine hangs, and sometimes NFS client machines display the following error message.

  NFS Stale File Handle

• Sample files for package program not included

  The AFS distribution does not include the sample files referred to in the chapter of the OpenAFS Administration Guide about the package program (the files formerly installed by convention in the etc, lib, and src subdirectories of the /afs/cellname/wsadmin directory). OpenAFS Quick Beginnings therefore does not include instructions for installing the sample files. If you wish to use the package program and the discussion in the OpenAFS Administration Guide is not sufficient to guide you, contact your AFS product support representative for assistance.