NAME

backup - Introduction to the backup command suite

DESCRIPTION

The commands in the backup command suite are the administrative interface to the AFS Backup System. There are several categories of commands in the suite:

The backup command interpreter interacts with two other processes:

In addition to the standard command line interface, the backup command suite provides an interactive interface, which has several useful features described in backup_interactive(8). Three of the commands in the suite are available only in interactive mode: backup jobs, backup kill, and backup quit

OPTIONS

The following options are available on many commands in the backup suite. The reference page for each command also lists them, but they are described here in greater detail.

-cell <cell name>

Names the cell in which to run the command. It is acceptable to abbreviate the cell name to the shortest form that distinguishes it from the other entries in the /etc/yfs/CellServDB file on the local machine. If the -cell argument is omitted, the command interpreter determines the name of the local cell by reading the following in order:

Do not combine the -cell and -localauth options. A command on which the -localauth flag is included always runs in the local cell whereas a command on which the -cell argument is included runs in the specified foreign cell.

The -cell argument is not available on commands issued in interactive mode. The cell defined when the backup command interpreter enters interactive mode applies to all commands issued during the interactive session.

-help

Prints the online help for this command. All other valid options are ignored.

-localauth

Constructs a server ticket using the server encryption key with the highest key version number in the local /etc/yfs/server/KeyFileExt file. The backup command interpreter presents the ticket, which never expires, to the Backup Server, Volume Server and Volume Location (VL) Server during mutual authentication.

Use this flag only when issuing a command on a server machine; client machines do not usually have a /etc/yfs/server/KeyFileExt file. The issuer of a command that includes this flag must be logged on to the server machine as the local superuser root. The flag is useful for commands invoked by an unattended application program, such as a process controlled by the UNIX cron utility or by a cron entry in the machine's /etc/yfs/server/BosConfig file. It is also useful if an administrator is unable to authenticate to AFS but is logged in as the local superuser root.

Do not combine the -cell and -localauth options. A command on which the -localauth flag is included always runs in the local cell whereas a command on which the -cell argument is included runs in the specified foreign cell.

The -localauth argument is not available on commands issued in interactive mode. The local identity and AFS tokens with which the backup command interpreter enters interactive mode apply to all commands issued during the interactive session.

-config <configuration file>

Sets the location of the configuration file to be used. The default file is /etc/yfs/yfs-client.conf.

-portoffset <TC port offset>

Specifies the port offset number of the Tape Coordinator that is to execute the backup command. The port offset number uniquely identifies a pairing of a Tape Coordinator (butc) process and tape device or backup data file.

The backup command interpreter and Tape Coordinator process communicate via a UDP socket, or port. Before issuing a backup command that involves reading or writing a tape, the backup operator must start a butc process that controls the appropriate tape device and listens for requests sent to its port number. If a Backup System machine has multiple tape devices attached, they can perform backup operations simultaneously because each device has its own associated butc process and port offset number.

The Backup System associates a tape capacity and file mark size with each port offset (as defined in the tapeconfig file). For a compressing tape device, the capacity and file mark values differ for compression and non-compression modes, so the two modes have distinct port offset numbers.

The Backup Database can store up to 58,511 port offsets, so the legal values for this argument are the integers 0 through 58510. If the issuer omits the argument, it defaults to 0. (The limit of 58,511 port offsets results from the fact that UDP socket numbers are identified by a 16-bit integer, and the lowest socket number used by the Backup System is 7025. The largest number that a 16-bit integer can represent is 65,535. Subtracting 7,025 yields 58,510. The addition of port offset 0 (zero) increases the maximum to 58,511.)

Although it is possible to define up to 58,511 port offset numbers for a cell, it is not possible to run 58,511 tape devices simultaneously, due to the following limits:

The Backup System does not reserve UDP sockets. If another application is already using the Tape Coordinator's socket when it tries to start, the butc process fails and the following error message appears at the shell prompt:

   bind: Address already in use
   rxi_GetUDPSocket: bind failed

PRIVILEGE REQUIRED

To issue any backup command that accesses the Backup Database only, the issuer must be listed in the /etc/yfs/server/UserListExt file on every machine where the Backup Server is running. To issue any backup command that accesses volume data, the issuer must appear in the UserListExt file on every Backup Server machine, every Volume Location (VL) Server machine, and every file server machine that houses affected volumes. By convention, a common UserListExt file is distributed to all database server and file server machines in the cell. See the chapter on privileged users in the OpenAFS Administration Guide for more information on this type of privilege.

If the -localauth flag is included, the user must instead be logged on as the local superuser root on the server machine where the backup command is issued.

SEE ALSO

BosConfig(5), CellServDB(5), KeyFileExt(5), UserListExt(5), butc(5), tapeconfig(5), backup_adddump(8), backup_addhost(8), backup_addvolentry(8), backup_addvolset(8), backup_apropos(8), backup_dbverify(8), backup_deldump(8), backup_deletedump(8), backup_delhost(8), backup_delvolentry(8), backup_delvolset(8), backup_diskrestore(8), backup_dump(8), backup_dumpinfo(8), backup_help(8), backup_interactive(8), backup_jobs(8), backup_kill(8), backup_labeltape(8), backup_listdumps(8), backup_listhosts(8), backup_listvolsets(8), backup_quit(8), backup_readlabel(8), backup_restoredb(8), backup_savedb(8), backup_scantape(8), backup_setexp(8), backup_status(8), backup_volinfo(8), backup_volrestore(8), backup_volsetrestore(8), buserver(8), butc(8)

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.

ACKNOWLEDGEMENTS

"AFS" is a registered mark of International Business Machines Corporation, used under license. (USPTO Registration 1598389)

"OpenAFS" is a registered mark of International Business Machines Corporation. (USPTO Registration 4577045)

The "AuriStor" name, log 'S' brand mark, and icon are registered marks of AuriStor, Inc. (USPTO Registrations 4849419, 4849421, and 4928460) (EUIPO Registration 015539653).

"Your File System" is a registered mark of AuriStor, Inc. (USPTO Registrations 4801402 and 4849418).

"YFS" and "AuriStor File System" are trademarks of AuriStor, Inc.