+++ /dev/null
-.\" Copyright (c) 1980, 1991, 1993
-.\" Regents of the University of California.
-.\" All rights reserved.
-.\"
-.\" Redistribution and use in source and binary forms, with or without
-.\" modification, are permitted provided that the following conditions
-.\" are met:
-.\" 1. Redistributions of source code must retain the above copyright
-.\" notice, this list of conditions and the following disclaimer.
-.\" 2. Redistributions in binary form must reproduce the above copyright
-.\" notice, this list of conditions and the following disclaimer in the
-.\" documentation and/or other materials provided with the distribution.
-.\" 3. All advertising materials mentioning features or use of this software
-.\" must display the following acknowledgement:
-.\" This product includes software developed by the University of
-.\" California, Berkeley and its contributors.
-.\" 4. Neither the name of the University nor the names of its contributors
-.\" may be used to endorse or promote products derived from this software
-.\" without specific prior written permission.
-.\"
-.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
-.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
-.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-.\" SUCH DAMAGE.
-.\"
-.\" @(#)dump.8 8.3 (Berkeley) 5/1/95
-.\" $Id: dump.8,v 1.3 1999/10/11 12:59:18 stelian Exp $
-.\"
-.Dd June 4, 1997
-.Dt DUMP 8
-.Os BSD 4
-.Sh NAME
-.Nm dump
-.Nd ext2 filesystem backup
-.Sh SYNOPSIS
-.Nm dump
-.Op Fl 0123456789acknu
-.Op Fl B Ar records
-.Op Fl b Ar blocksize
-.Op Fl d Ar density
-.Op Fl f Ar file
-.Op Fl h Ar level
-.Op Fl L Ar label
-.Op Fl s Ar feet
-.Op Fl T Ar date
-.Ar filesystem
-.Nm dump
-.Op Fl 0123456789acknu
-.Op Fl B Ar records
-.Op Fl b Ar blocksize
-.Op Fl d Ar density
-.Op Fl f Ar file
-.Op Fl h Ar level
-.Op Fl L Ar label
-.Op Fl s Ar feet
-.Op Fl T Ar date
-.Ar directory
-.Nm dump
-.Op Fl W Li \&| Fl w
-.Pp
-.in -\\n(iSu
-(The
-.Bx 4.3
-option syntax is implemented for backward compatibility but
-is not documented here.)
-.Sh DESCRIPTION
-.Nm Dump
-examines files
-on an ext2 filesystem
-and determines which files
-need to be backed up. These files
-are copied to the given disk, tape or other
-storage medium for safe keeping (see the
-.Fl f
-option below for doing remote backups).
-A dump that is larger than the output medium is broken into
-multiple volumes.
-On most media the size is determined by writing until an
-end-of-media indication is returned. This can be enforced
-by using the
-.Fl a
-option.
-.Pp
-On media that cannot reliably return an end-of-media indication
-(such as some cartridge tape drives),
-each volume is of a fixed size;
-the actual size is determined by the tape size, density and/or
-block count options below.
-By default, the same output file name is used for each volume
-after prompting the operator to change media.
-.Pp
-The following options are supported by
-.Nm Ns :
-.Bl -tag -width Ds
-.It Fl 0\-9
-Dump levels.
-A level 0, full backup,
-guarantees the entire file system is copied
-(but see also the
-.Fl h
-option below).
-A level number above 0,
-incremental backup,
-tells
-.Nm dump
-to
-copy all files new or modified since the
-last dump of the same or lower level.
-The default level is 9.
-.It Fl B Ar records
-The number of 1 KB blocks per volume.
-This option overrides the calculation of tape size
-based on length and density.
-.It Fl a
-.Dq auto-size .
-Bypass all tape length considerations, and enforce writing
-until an end-of-media indication is returned. This fits best
-for most modern tape drives. Use of this option is particularly
-recommended when appending to an existing tape, or using a tape
-drive with hardware compression (where you can never be sure about
-the compression ratio).
-.It Fl b Ar blocksize
-The number of kilobytes per dump record.
-Since the IO system slices all requests into chunks of MAXBSIZE
-(typically 64KB), it is not possible to use a larger blocksize
-without having problems later with
-.Xr restore 8 .
-Therefore
-.Nm dump
-will constrain writes to MAXBSIZE.
-.It Fl c
-Change the defaults for use with a cartridge tape drive, with a density
-of 8000 bpi, and a length of 1700 feet.
-.It Fl h Ar level
-Honor the user
-.Dq nodump
-flag
-.Dp Dv UF_NODUMP
-only for dumps at or above the given
-.Ar level .
-The default honor level is 1,
-so that incremental backups omit such files
-but full backups retain them.
-.It Fl d Ar density
-Set tape density to
-.Ar density .
-The default is 1600BPI.
-.It Fl f Ar file
-Write the backup to
-.Ar file ;
-.Ar file
-may be a special device file
-like
-.Pa /dev/st0
-(a tape drive),
-.Pa /dev/rsd1c
-(a floppy disk drive),
-an ordinary file,
-or
-.Ql Fl
-(the standard output).
-Multiple file names may be given as a single argument separated by commas.
-Each file will be used for one dump volume in the order listed;
-if the dump requires more volumes than the number of names given,
-the last file name will used for all remaining volumes after prompting
-for media changes.
-If the name of the file is of the form
-.Dq host:file
-or
-.Dq user@host:file
-.Nm
-writes to the named file on the remote host using
-.Xr rmt 8 .
-The default path name of the remote
-.Xr rmt 8
-program is
-.\" rmt path, is the path on the remote host
-.Pa /etc/rmt ;
-this can be overridden by the environment variable
-.Ev RMT .
-.It Fl k
-Use Kerberos authentication to talk to remote tape servers. (Only
-available if this option was enabled when
-.Nm
-was compiled.)
-.It Fl L Ar label
-The user-supplied text string
-.Ar label
-is placed into the dump header, where tools like
-.Xr restore 8
-and
-.Xr file 1
-can access it.
-Note that this label is limited
-to be at most LBLSIZE (currently 16) characters, which must include
-the terminating
-.Ql \e0 .
-.It Fl n
-Whenever
-.Nm
-requires operator attention,
-notify all operators in the group
-.Dq operator
-by means similar to a
-.Xr wall 1 .
-.It Fl s Ar feet
-Attempt to calculate the amount of tape needed
-at a particular density.
-If this amount is exceeded,
-.Nm
-prompts for a new tape.
-It is recommended to be a bit conservative on this option.
-The default tape length is 2300 feet.
-.ne 1i
-.It Fl T Ar date
-Use the specified date as the starting time for the dump
-instead of the time determined from looking in
-.Pa /etc/dumpdates .
-The format of
-.Ar date
-is the same as that of
-.Xr ctime 3 .
-This option is useful for automated dump scripts that wish to
-dump over a specific period of time.
-The
-.Fl T
-option is mutually exclusive from the
-.Fl u
-option.
-.It Fl u
-Update the file
-.Pa /etc/dumpdates
-after a successful dump.
-The format of
-.Pa /etc/dumpdates
-is readable by people, consisting of one
-free format record per line:
-filesystem name,
-increment level
-and
-.Xr ctime 3
-format dump date.
-There may be only one entry per filesystem at each level.
-The file
-.Pa /etc/dumpdates
-may be edited to change any of the fields,
-if necessary.
-.It Fl W
-.Nm Dump
-tells the operator what file systems need to be dumped.
-This information is gleaned from the files
-.Pa /etc/dumpdates
-and
-.Pa /etc/fstab .
-The
-.Fl W
-option causes
-.Nm
-to print out, for each file system in
-.Pa /etc/dumpdates ,
-the most recent dump date and level,
-and highlights those file systems that should be dumped.
-If the
-.Fl W
-option is set, all other options are ignored, and
-.Nm
-exits immediately.
-.It Fl w
-Is like
-.Fl W ,
-but prints only those filesystems which need to be dumped.
-.El
-.Pp
-.Nm Dump
-requires operator intervention on these conditions:
-end of tape,
-end of dump,
-tape write error,
-tape open error or
-disk read error (if there is more than a threshold of 32).
-In addition to alerting all operators implied by the
-.Fl n
-key,
-.Nm
-interacts with the operator on
-.Em dump's
-control terminal at times when
-.Nm
-can no longer proceed,
-or if something is grossly wrong.
-All questions
-.Nm
-poses
-.Em must
-be answered by typing
-.Dq yes
-or
-.Dq no ,
-appropriately.
-.Pp
-Since making a dump involves a lot of time and effort for full dumps,
-.Nm
-checkpoints itself at the start of each tape volume.
-If writing that volume fails for some reason,
-.Nm
-will,
-with operator permission,
-restart itself from the checkpoint
-after the old tape has been rewound and removed,
-and a new tape has been mounted.
-.Pp
-.Nm Dump
-tells the operator what is going on at periodic intervals,
-including usually low estimates of the number of blocks to write,
-the number of tapes it will take, the time to completion, and
-the time to the tape change.
-The output is verbose,
-so that others know that the terminal
-controlling
-.Nm
-is busy,
-and will be for some time.
-.Pp
-In the event of a catastrophic disk event, the time required
-to restore all the necessary backup tapes or files to disk
-can be kept to a minimum by staggering the incremental dumps.
-An efficient method of staggering incremental dumps
-to minimize the number of tapes follows:
-.Bl -bullet -offset indent
-.It
-Always start with a level 0 backup, for example:
-.Bd -literal -offset indent
-/sbin/dump -0u -f /dev/nrst1 /usr/src
-.Ed
-.Pp
-This should be done at set intervals, say once a month or once every two months,
-and on a set of fresh tapes that is saved forever.
-.It
-After a level 0, dumps of active file
-systems are taken on a daily basis,
-using a modified Tower of Hanoi algorithm,
-with this sequence of dump levels:
-.Bd -literal -offset indent
-3 2 5 4 7 6 9 8 9 9 ...
-.Ed
-.Pp
-For the daily dumps, it should be possible to use a fixed number of tapes
-for each day, used on a weekly basis.
-Each week, a level 1 dump is taken, and
-the daily Hanoi sequence repeats beginning with 3.
-For weekly dumps, another fixed set of tapes per dumped file system is
-used, also on a cyclical basis.
-.El
-.Pp
-After several months or so, the daily and weekly tapes should get
-rotated out of the dump cycle and fresh tapes brought in.
-.Sh ENVIRONMENT
-.Bl -tag -width Fl
-.It Ev TAPE
-If no -f option was specified,
-.Nm
-will use the device specified via
-.Ev TAPE
-as the dump device.
-.Ev TAPE
-may be of the form
-.Qq tapename ,
-.Qq host:tapename ,
-or
-.Qq user@host:tapename .
-.It Ev RMT
-The environment variable
-.Ev RMT
-will be used to determine the pathname of the remote
-.Xr rmt 8
-program.
-.Sh FILES
-.Bl -tag -width /etc/dumpdates -compact
-.It Pa /dev/st0
-default tape unit to dump to
-.It Pa /etc/dumpdates
-dump date records
-.It Pa /etc/fstab
-dump table: file systems and frequency
-.It Pa /etc/group
-to find group
-.Em operator
-.El
-.Sh SEE ALSO
-.Xr fstab 5 ,
-.Xr restore 8 ,
-.Xr rmt 8
-.Sh DIAGNOSTICS
-Many, and verbose.
-.Pp
-.Nm Dump
-exits with zero status on success.
-Startup errors are indicated with an exit code of 1;
-abnormal termination is indicated with an exit code of 3.
-.Sh BUGS
-It might be considered a bug that this version of dump can only handle ext2
-filesystems. Specifically, it does not work with FAT filesystems.
-.Pp
-Fewer than 32 read errors on the filesystem are ignored. If noticing
-read errors is important, the output from dump can be parsed to look for lines
-that contain the text 'read error'.
-.Pp
-Each reel requires a new process, so parent processes for
-reels already written just hang around until the entire tape
-is written.
-.Pp
-.Nm Dump
-with the
-.Fl W
-or
-.Fl w
-option does not report filesystems that have never been recorded
-in
-.Pa /etc/dumpdates ,
-even if listed in
-.Pa /etc/fstab .
-.Pp
-It would be nice if
-.Nm
-knew about the dump sequence,
-kept track of the tapes scribbled on,
-told the operator which tape to mount when,
-and provided more assistance
-for the operator running
-.Xr restore .
-.Pp
-.Nm Dump
-cannot do remote backups without being run as root, due to its
-security history. This will be fixed in a later version of
-.Bx Free .
-Presently, it works if you set it setuid (like it used to be), but this
-might constitute a security risk.
-.Sh HISTORY
-A
-.Nm
-command appeared in
-.At v6 .
git.wh0rd.org / dump.git / blobdiff