1DUMP(1M) DUMP(1M)
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6 dump - incremental file system dump
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9 dump [ key [ argument ... ] filesystem ]
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12 Dump copies to magnetic tape all files changed after a certain date in
13 the filesystem. The key specifies the date and other options about the
14 dump. Key consists of characters from the set 0123456789fusd.
15 f Place the dump on the next argument file instead of the tape.
17 u If the dump completes successfully, write the date of the begin‐
19 ning of the dump on file `/etc/ddate'. This file records a sepa‐
20 rate date for each filesystem and each dump level.
21 0-9 This number is the `dump level'. All files modified since the
23 last date stored in the file `/etc/ddate' for the same filesystem
24 at lesser levels will be dumped. If no date is determined by the
25 level, the beginning of time is assumed; thus the option 0 causes
26 the entire filesystem to be dumped.
27 s The size of the dump tape is specified in feet. The number of
29 feet is taken from the next argument. When the specified size is
30 reached, the dump will wait for reels to be changed. The default
31 size is 2300 feet.
32 d The density of the tape, expressed in BPI, is taken from the next
34 argument. This is used in calculating the amount of tape used per
35 write. The default is 1600.
36 If no arguments are given, the key is assumed to be 9u and a default
38 file system is dumped to the default tape.
39 Now a short suggestion on how perform dumps. Start with a full level 0
41 dump
42 dump 0u
44 Next, periodic level 9 dumps should be made on an exponential progres‐
46 sion of tapes. (Sometimes called Tower of Hanoi - 1 2 1 3 1 2 1 4 ...
47 tape 1 used every other time, tape 2 used every fourth, tape 3 used
48 every eighth, etc.)
49 dump 9u
51 When the level 9 incremental approaches a full tape (about 78000 blocks
53 at 1600 BPI blocked 20), a level 1 dump should be made.
54 dump 1u
56 After this, the exponential series should progress as uninterrupted.
58 These level 9 dumps are based on the level 1 dump which is based on the
59 level 0 full dump. This progression of levels of dump can be carried
60 as far as desired.
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63 default filesystem and tape vary with installation.
64 /etc/ddate: record dump dates of filesystem/level.
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67 restor(1), dump(5), dumpdir(1)
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70 If the dump requires more than one tape, it will ask you to change
71 tapes. Reply with a new-line when this has been done.
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74 Sizes are based on 1600 BPI blocked tape. The raw magtape device has
75 to be used to approach these densities. Read errors on the filesystem
76 are ignored. Write errors on the magtape are usually fatal.
77 DUMP(1M)