help.client

一套客户/服务器模式的备份系统代码,跨平台,支持linux,AIX, IRIX, FreeBSD, Digital Unix (OSF1), Solaris and HP-UX.

Description
===========

This program is used to maintain archives on a backup server
host or in a file. Archives can be created, extracted or their
contents be listed. At least one of the following flags has to
be supplied:

 -c  to create an archive

 -x  to extract from an archive

 -t  to list the contents of an archive

 -d  to verify (compare) the contents of an archive

 -C  to set a certain cartridge on the backup server
       (makes only sense extracting or listing with -x or
        -t, the writing position can't be changed by clients)

 -F  to set a certain file on the backup server's tape
       (the same applies as for -C)

 -q  to printout the current cartridge and tape file number
       on the backup server

 -Q  to printout the cartridge and tape file number for the
       the next write access on the backup server

 -X  followed by the full path name of a program to be started on
       the client. This can be used to trigger a backup remotely.
       If the program needs arguments, the command together with
       the arguments has to be enclosed by quotes

 -I  to printout an index of the backups written to the current
       cartridge

 -w  to check the status of the streamer on the server side, e.g.
       whether it is ready and waiting for requests to service

 -G  to request a new cartridge for the next writing operation.
       If the current writing position is already at the beginning
       of a new or reused tape, nothing happens

 -D <destination> to make an exact copy of a tape to another one
       (duplicate). See below how to specify the destination tape.
       Duplication can be either from one cartridge to another on
       the same server, or from one server to another one. When
       copying to the same server chunks of data are stored in a
       temporary directory on the client, where the command is
       started, what should preferably be the source server

 -M <message> send a message to the server. Messages will in the
       most cases contain whitespace, so they should be enclosed
       in quotes. Server messages should be sent to the single
       stream server (port), the multi stream server might hang
       receiving a message due to systematical reasons. Several
       messages can be put into the string. They must be separated
       by a real newline character or the usual C-like \n .
       The following messages are currently supported:

        PreciousTapes: <list-of-tapes>
                   The list of tapes is inserted into the table
                   with the tapes, that are crucial for clients
                   to restore all files, that are listed in all
                   existing index files. These tapes will not be
                   overwritten until explicitly permitted. This
                   message is generated automatically and should
                   not be used in other user contexts

        ReuseTapes: <list-of-tapes>
                   The opposite of PreciousTapes. Sending this
                   message permits the server to overwrite the
                   listed tapes, though they are crucial for
                   some client

        TapesReadOnly: <list-of-tapes>
                   The list of tapes is inserted into the file
                   listing the files, that should not be written
                   any more for whatever reason

        TapesReadWrite: <list-of-tapes>
                   This reverts the status of tapes set read-only
                   to read-write, the opposite of TapesReadOnly

        CartridgeReady
                   When an operator is requested to do something
                   the server is waiting for, this message can be
                   sent to trigger the server to proceed. This
                   message has the same effect as the cartready
                   command

        DeleteClient: <client-identifier>
                   The tapes, that are marked as reserved for a
                   client to recover all the data in his indexes,
                   are freed. That is, the appropriate line is
                   removed from the server's precious_tapes file

 -m [ <interval> ] poll the current message from the server and
       write it to standard output, if it is new. Polling is
       done regularly with the given interval in seconds, default
       interval is 3 seconds

-c, -x, -t, -d, -X, -D and -I are mutual exclusive. The other
options can be supplied as needed. To set the cartridge and/or
the tape file on the backup server is only making sense when not
creating an archive. The serial order of writing to tape is
handled by the server machine independently of the client.


Filenames

The names of the files and directories, that have to be put
into or extracted from an archive are by default read from the
standard input. If filenames are supplied in the command line
the -a flag is given when extracting, standard input is not read.
The same applies, when filenames are read from a file with the
-T option. When reading the names from a file or from standard
input, they must be given one per line. If a name contains
special characters (like newline or nonprintable ones), they
have to be specified using backslash-sequences like in C-code,
e.g. \n for newline.
In save mode (-c) filenames can be prefixed with character
sequences, that have special meanings (no space between prefix
and filename):

 /../   The file is not saved with all attributes present in
        the inode, but only the contents are saved. This might
        be useful for saving raw-devices
 //../  With /../ the configured processing is not applied to
        the file contents for safety reasons. With this prefix
        processing can be forced nonetheless
 |||    and a mandatory space character indicates, that the
        following characters up to (but not including) another
        triple bar ||| should be interpreted as a shell command,
        that is started and whose standard output is written to
        the backup. At restore time the command following the
        second triple bar is started and the data stream read
        at backup time is written to it's standard input. This
        might be useful for saving e.g. databases. The second
        command may be terminated by a triple sharp ###, that
        starts an optional comment. Example:
        ||| pg_dumpall ||| psql db_tmpl ### Store Postgres DBs


Destination

The destination tape for the duplicate operation can be given
in two ways: either with the options -h, -p, -C and -k following
the -D immediately without space and enclosed in quotes, so that
they appear as an own argument list in one real argument, e.g.:
 -D' -C 5 -h targethost -p targetport'
(double quotes are of course also possible ...).
The second format is as follows:
 [<targetcart>][@<targethost>][%targetport>][:<targetcryptkeyfile>]
At least one of the specifiers must be present. Examples:
 5@otherhost  5%2990:/keyfile/for/target/server @otherhost%2970
If one of the specifiers is omitted, it is assumed identical with
the copy source specified in the normal options -h, -p, -C and -k.
Copying a tape to itself is prevented.


More options in alphabetical order:

 -            in combination with -c: read standard input and
                write it to tape, in combination with -x: read
                tape and write it to standard output

 -A <time>    process files (save or extract) modified after
                the given time in seconds since 1.1.1970 00:00

 -a           in combination with -x: extract all files and
                directories in the archive

 -B <time>    process files (save or extract) modified before
                the given time in seconds since 1.1.1970 00:00

 -b           don't enter buffering mode

 -e <errlog>  Use the file <errlog> to write error messages to
                instead of the standard error output

 -f <file>    write to or read from a file instead of querying
                the backup server

 -g           while extracting/reading: ignore leading garbage,
                suppress error messages at the beginning. This
                is useful when extracting from tape files, that
                are not the first ones of a whole archive.

 -H <header>  put the supplied informational header to the begin
                of the backup. If a - is supplied (no space may
                follow -H i.e. -H-) the information is read from
                the first line of stdin. Backslash sequences of
                C-like style are replaced

 -h <host>    use the backup server with the name <host>
                default host is the machine with the name
                backuphost

 -i           while extracting: ignore the stored ownership and
                do not restore it

 -j           when starting to write: request starting a new
                tape file

 -K           when packing, do not keep the access time of the
                file. By default after packing a filesystem entry
                it's previous atime is restored

 -k <file>    use the contents of the given file as encryption
                key for authenticating to the server

 -l           for each packed or unpacked filename, if sending
                to or receiving from a backup server in verbose
                   mode in combination with -n:
                printout server name and port number at the
                beginning of the line, e.g.: orion%2988!

 -N <file>    while archiving: ignore files with a modification
                time before the one of the given file, only save
                newer files or such with the same age in seconds

 -n           for each packed or unpacked filename, if sending
                to or receiving from a backup server in verbose
                   mode:
                printout cartridge and tape file number at the
                beginning of the line, e. g.: 7.15: <filename>
                In combination with -X: precede each line of
                output received from the remotely started program
                with the identifier of the remote host and a
                colon, e. g.:  darkstar: Full backup finished.

 -O           for each packed file creating a backup in verbose
                mode: printout the user-ID of the file owner at
                the beginning of the line prefixed with a bar |
                eventually behind cartridge and file number

 -o <uid>     archive or extract only files owned by the user
                with the given user-ID (an integer)

 -p <portno>  use a different port number for communicating with
                the backup server. Default is TCP-Port 2988

 -R           pack or extract directories recursively with all
                of their contents

 -r           use filenames relative to the current directory,
                whether they start with a slash or not. If -r
                is given more then 1 time, also let symlinks
                originally pointing to absolute paths now point
                to paths relative to the directory, where the
                symlink will be created

 -S <cartset> The cartridge set to use, where <cartset> is the
                number of a valid cartridge set on the server
                side. Default is 1. This option makes sense only
                when creating backups with -c

 -s <filepat> do not attempt processing on files matching the
                given filename pattern. This parameter may
                appear several times

 -T <file/dir> read the filenames to process from the <file>.
                The filenames must be separated by whitespace.
                If whitespace is part of a filename, it has to
                be enclosed by double quotes. Double quotes or
                backslashes within the filename have to be
                preceded by a backslash. In combination with
                -D: the tape files to be copied are temporarily
                stored in the given directory instead of the
                default directory /tmp

 -U           for each packed file creating a backup in verbose
                mode: printout the modification time of the file
                in seconds since 1970/1/1 0:00 at the beginning
                of the line prefixed with a tilde ~ eventually
                behind cartridge number, file number and owner

 -u           while extracting: remove existing files with the
                same name as found in the archive. Otherwise
                no existing files are overwritten

 -V <file>    write a report containing statistics at the end of
                a backup to the <file>

 -v           verbose mode: print the filenames while creating
                or extracting, be a little more verbose while
                listing contents. If -v is the only given flag:
                print out software name and version

 -W <id>      identify as <id> to the server. This is needed when
                connecting a multi-stream server to distinguish
                between the clients. Default is the string
                "<client-program>"

 -z <z> <uz>  use <z> as the command, that is used to process
                files, <uz> for the corresponding unprocess.
                The command has to read from stdin and to write
                to stdout. If arguments have to be supplied to
                <z> and/or <uz>, don't forget to use quotes. If
                built-in compression is desired, the command for
                processing has to start with a dot (.), followed
                by a space and a number ranging from 1 to 9, that
                specifies the compression level. If an additional
                external command should process the data, it may
                follow, separated from the compression level by
                whitespace. The order of processing is: First the
                external program processes the data, then built-in
                compression is applied. An empty string has to be
                supplied for <uz> (or any other dummy is ok), if
                only built-in compression is desired.
                Examples for <z>:
                 gzip       (run external command gzip),
                 "gzip -2"  (the same with an argument),
                 ". 8"      (only built-in compression level 8),
                 ". 3 __descrpt -k /my/key" (run command __descrpt
                            and apply built-in compression level 3)

 -Z           while printing out the contents: check those files
                in the archive that are processed for integrity.
                While creating an archive: write a CRC32 checksum
                for each file, file contents or command output to
                the backup stream


 -?           to printout this text