1merge(8) System Manager's Manual merge(8)
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6 merge - merge incremental dumps onto full dumps for restore
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10 merge <output file> <full dump> <incremental dump>
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13 merge is a utility that allows one to apply incremental dumps to a full
14 dump and produce a new full dump which reflects a later state of the
15 volume. The new dump can then be used to restore the volume, or can be
16 merged with other incrementals.
17 An incremental or full dump reflects the state of the volume at the
19 time it was dumped. Full dumps can be restored so that a user may
20 access an older state of a volume. Incremental dumps do not necessarily
21 have sufficient information to be restored. For instance, all the
22 vnodes in the dump may not be present. The merging process allows a
23 full image of a state that was only incrementally dumped to be
24 restored.
25 Currently incrementals apply to the last successful full dump that was
27 done. As an example, say full dumps for a volume are done on Sundays,
28 with incrementals being taken the rest of the week. If an administrator
29 wishes to restore a volume to Wednesdays state, he would have to fetch
30 the full dumpfile from Sunday and the incremental dumpfile for Wednes‐
31 day. Once these are present, the administrator would use the merge pro‐
32 gram to create a new updated full dump for Wednesdays state, and
33 restore it to the server (using volutil(8) restore).
34 Information in the dump header is used to place a total ordering on the
36 dumps. This way incrementals can only be applied to the dump with
37 repect to which they were taken. In addition, incrementals cannot be
38 applied to other incrementals, and the dumps to be merged must have
39 been created from the same volume replica. The merge program checks
40 these things, and reports failures if they are violated.
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43 volutil (8), restore (1)
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46 David C. Steere, 1991, created
47 merge(8)