1DUMP(8)                     System Manager's Manual                    DUMP(8)
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NAME

6       dump - incremental file system dump
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SYNOPSIS

9       dump [0123456789BchfusTdWwn [argument ...]] [filesystem]
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DESCRIPTION

12       Dump  copies to magnetic tape all files changed after a certain date in
13       the filesystem.
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15       The following options are supported by dump:
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17       0-9  This number is the `dump level'.  All  files  modified  since  the
18            last  date stored in the file /etc/dumpdates for the same filesys‐
19            tem at lesser levels will be dumped.  If no date is determined  by
20            the  level,  the  beginning  of time is assumed; thus the option 0
21            causes the entire filesystem to be dumped.
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23       B records
24            The number of dump records per volume.  This option overrides  the
25            calculation of tape size based on length and density.
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27       c    This option requires no further options.  Used to specify that the
28            tape is a cartridge drive rather than a 9-track.
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30       h level
31            Honor the user 'nodump' flags only for dumps at or above the given
32            level.   The default honor level is 1, so that incremental backups
33            omit such files but full backups retain them.
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35       f    Place the dump on the next argument file instead of the tape.   If
36            '-' is given then standard out (stdout) is written to.
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38       u    If  the  dump completes successfully, write the date of the begin‐
39            ning of the dump on file /etc/dumpdates.  This file records a sep‐
40            arate date for each filesystem and each dump level.  The format of
41            /etc/dumpdates is readable by people, consisting of one free  for‐
42            mat record per line: filesystem name, increment level and ctime(3)
43            format dump date.  /etc/dumpdates may be edited to change  any  of
44            the fields, if necessary.  Note that /etc/dumpdates is in a format
45            different from that which previous versions of dump maintained  in
46            /etc/ddate, although the information content is identical.
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48       s    The  size  of  the  dump tape is specified in feet.  The number of
49            feet is taken from the next argument.  When the specified size  is
50            reached, dump will wait for reels to be changed.  The default tape
51            size is 2300 feet.
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53       d    The density of the tape, expressed in BPI, is taken from the  next
54            argument.  This is used in calculating the amount of tape used per
55            reel. The default is 1600.
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57       T date
58            Use the specified date as the starting time for the  dump  instead
59            of the time determined from looking in /etc/dumpdates.  The format
60            of date is the same as that of ctime(3).  This  option  is  useful
61            for  automated  dump  scripts  that  wish  to dump over a specific
62            period of time.  The T option is mutually  exclusive  with  the  u
63            option.
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65       W    Dump tells the operator what file systems need to be dumped.  This
66            information  is  gleaned  from  the   files   /etc/dumpdates   and
67            /etc/fstab.   The W option causes dump to print out, for each file
68            system in /etc/dumpdates the most recent dump date and level,  and
69            highlights  those  file  systems  that should be dumped.  If the W
70            option is set, all other options are ignored, and dump exits imme‐
71            diately.
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73       w    Is  like  W,  but  prints  only those filesystems which need to be
74            dumped.
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76       n    Whenever dump requires operator attention, notify by means similar
77            to a wall(1) all of the operators in the group “operator”.
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79       If  no  arguments  are given, the key is assumed to be 9u and a default
80       file system is dumped to the default tape.
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82       Dump requires operator intervention on these conditions: end  of  tape,
83       end  of  dump, tape write error, tape open error or disk read error (if
84       there are more than a threshold of 32).  In addition  to  alerting  all
85       operators  implied  by  the  n key, dump interacts with the operator on
86       dump's control terminal at times when dump can no longer proceed, or if
87       something  is grossly wrong.  All questions dump poses must be answered
88       by typing “yes” or “no”, appropriately.
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90       Since making a dump involves a lot of time and effort for  full  dumps,
91       dump  checkpoints  itself at the start of each tape volume.  If writing
92       that volume fails for some reason, dump will, with operator permission,
93       restart  itself from the checkpoint after the old tape has been rewound
94       and removed, and a new tape has been mounted.
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96       Dump tells the operator what is going on at periodic intervals, includ‐
97       ing  usually low estimates of the number of blocks to write, the number
98       of tapes it will take, the time to completion, and the time to the tape
99       change.   The  output is verbose, so that others know that the terminal
100       controlling dump is busy, and will be for some time.
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102       Now a short suggestion on how to perform  dumps.   Start  with  a  full
103       level 0 dump
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105            dump 0un
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107       Next,  dumps of active file systems are taken on a daily basis, using a
108       modified Tower of Hanoi algorithm, with this sequence of dump levels:
109                               3 2 5 4 7 6 9 8 9 9 ...
110       For the daily dumps, a set of 10 tapes per dumped file system  is  used
111       on a cyclical basis.  Each week, a level 1 dump is taken, and the daily
112       Hanoi sequence repeats with 3.  For weekly dumps, a set of 5 tapes  per
113       dumped  file  system  is used, also on a cyclical basis.  Each month, a
114       level 0 dump is taken on a set of fresh tapes that is saved forever.
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FILES

117       /dev/rxp0a      default filesystem to dump from
118       /dev/rmt0       default tape unit to dump to
119       /etc/ddate      old format dump date record (obsolete after -J option)
120       /etc/dumpdates  new format dump date record
121       /etc/fstab      Dump table: file systems and frequency
122       /etc/group      to find group operator
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SEE ALSO

125       restor(8), rdump(8), dump(5), fstab(5), dumpdir(8)
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DIAGNOSTICS

128       Many, and verbose.
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BUGS

131       Sizes are based on 1600 BPI blocked tape; the raw magtape device has to
132       be  used to approach these densities.  Fewer than 32 read errors on the
133       filesystem are ignored.  Each reel requires a new  process,  so  parent
134       processes  for  reels already written just hang around until the entire
135       tape is written.
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137       It would be nice if dump knew about the dump sequence,  kept  track  of
138       the tapes scribbled on, told the operator which tape to mount when, and
139       provided more assistance for the operator running restor.
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1434th Berkeley Distribution                                              DUMP(8)
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