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diff --git a/sbin/dump/dump.8 b/sbin/dump/dump.8 new file mode 100644 index 000000000000..2cd9335c454e --- /dev/null +++ b/sbin/dump/dump.8 @@ -0,0 +1,335 @@ +.\" 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 8.1 (Berkeley) 6/16/93 +.\" +.Dd June 16, 1993 +.Dt DUMP 8 +.Os BSD 4 +.Sh NAME +.Nm dump +.Nd filesystem backup +.Sh SYNOPSIS +.Nm dump +.Op Cm 0123456789BbhfusTdWn Op Ar argument ... +.Op Ar filesystem +.Sh DESCRIPTION +.Nm Dump +examines files +on a 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 +.Cm 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. +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 and 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 dump: +.Bl -tag -width 4n +.It Cm 0\-9 +Dump levels. +A level 0, full backup, +guarantees the entire file system is copied +(but see also the +.Cm h +option below). +A level number above 0, +incremental backup, +tells dump to +copy all files new or modified since the +last dump of the same or lower level. The default +level is 9. +.It Cm B Ar records +The number of dump records per volume. +This option overrides the calculation of tape size +based on length and density. +.It Cm b Ar blocksize +The number of kilobytes per dump record. +.It Cm 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 Cm f Ar file +Write the backup to +.Ar file ; +.Ar file +may be a special device file +like +.Pa /dev/rmt12 +(a tape drive), +.Pa /dev/rsd1c +(a 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 dump +writes to the named file on the remote host using +.Xr rmt 8 . +.It Cm d Ar density +Set tape density to +.Ar density . +The default is 1600BPI. +.It Cm n +Whenever +.Nm dump +requires operator attention, +notify all operators in the group +.Dq operator +by means similar to a +.Xr wall 1 . +.It Cm s Ar feet +Attempt to calculate the amount of tape needed +at a particular density. +If this amount is exceeded, +.Nm dump +prompts for a new tape. +It is recommended to be a bit conservative on this option. +The default tape length is 2300 feet. +.It Cm 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 Cm 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 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 +.Cm T +option is mutually exclusive from the +.Cm u +option. +.It Cm 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 +.Cm W +option causes +.Nm dump +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 +.Cm W +option is set, all other options are ignored, and +.Nm dump +exits immediately. +.It Cm w +Is like 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 are more than a threshold of 32). +In addition to alerting all operators implied by the +.Cm n +key, +.Nm dump +interacts with the operator on +.Em dump's +control terminal at times when +.Nm dump +can no longer proceed, +or if something is grossly wrong. +All questions +.Nm dump +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 dump +checkpoints itself at the start of each tape volume. +If writing that volume fails for some reason, +.Nm dump +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 dump +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 +/etc/dump 0uf /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 FILES +.Bl -tag -width /etc/dumpdates -compact +.It Pa /dev/rmt8 +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 restore 8 , +.Xr rmt 8 , +.Xr dump 5 , +.Xr fstab 5 +.Sh DIAGNOSTICS +Many, and verbose. +.Pp +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 +.Pp +Fewer than 32 read errors on the filesystem are ignored. +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 +.Cm W +or +.Cm w +options 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 dump +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 . +.Sh HISTORY +A +.Nm dump +command appeared in Version 6 AT&T UNIX. |