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33 .\" $DragonFly: src/sbin/hammer/hammer.8,v 1.7 2008/02/23 20:55:21 dillon Exp $
39 .Nd HAMMER file system utility
43 .Op Fl f Ar blkdev[:blkdev]*
49 utility provides miscellanious functions related to managing a HAMMER
52 The options are as follows:
53 .Bl -tag -width indent
57 Specify recursion for those commands which support it.
58 .It Fl f Ar blkdev[:blkdev]*
59 Specify the volumes making up a HAMMER filesystem.
61 Increase verboseness. May be specified multiple times.
64 The commands are as follows:
65 .Bl -tag -width indent
67 Generate a timestamp suitable for use in the @@ filename extension,
68 representing right now.
70 Generate a timestamp suitable for use in the @@ filename extension.
71 A time specification of
72 .Pf yyyymmdd Oo :hhmmss Oc Ns Op .fractional
73 specifies an exact as-of timestamp in local (not UTC) time.
74 Set the TZ environment variable prior to running
76 if you wish to specify the time by some other means.
77 .It Ar history Ar path
78 Show the modification history for a HAMMER file's inode and data.
79 .It Ar show Op vol_no[:clu_no]
80 Dump the B-Tree starting at the specified volume and cluster, or
81 at the root volume if not specified.
82 The B-Tree is dumped recursively if the
86 Dump the btree, record, large-data, and small-data blockmaps, showing
87 physical block assignments and free space percentages.
88 .It Ar namekey Ar filename
89 Generate a HAMMER 64 bit directory hash for the specified file name.
90 The low 32 bits are used as an iterator for hash collisions and will be
92 .It Ar namekey32 Ar filename
93 Generate the top 32 bits of a HAMMER 64 bit directory hash for the specified
95 .It Ar prune Ar filesystem Ar from Ar #{smhdMy} Ar to Ar #{smhdMy} Ar every Ar #{smhdMy}
96 .It Ar prune Ar filesystem Ar everything
97 .It Ar prune Ar filesystem Op Ar using Ar filename
98 Prune the filesystem, removing deleted records to free up physical disk
99 space. Specify a time range between the nearest modulo 0 boundary
100 and prune the tree to the specified granularity within that range.
102 The filesystem specification should be the root of any mounted HAMMER
103 filesystem. This command uses a filesystem ioctl to issue the pruning
104 operation. If you specify just the filesystem with no other parameters
105 all prune directives matching that filesystem in the /etc/hammer.conf file
106 will be used. If you specify a
108 file then those directives contained in the file matching
110 will be used. Multiple directives may be specified when extracting from
111 a file. The directives must be in the same format: "prune ....", in
112 ascending time order (per filesystem). Matching prune elements must not
113 have overlapping time specifications.
115 Both the "from" and the "to" value must be an integral multiple
116 of the "every" value, and the "to" value must be an integral multiple
117 of the "from" value. When you have multiple pruning rules you must
118 take care to ensure that the range being pruned does not overlap ranges
119 pruned later on, when the retained data is older. If they do the retained
120 data can wind up being destroyed. For example, if you prune your data
121 on a 30 minute granularity for the last 24 hours any later pruning must
122 use a granularity that is a multiple of 30 minutes. If you prune your
123 data on a 30 minute boundary, then a 1 day boundary in a later pruning (on
124 older data), then a pruning beyond that would have to be a multiple of
127 The "prune <filesystem> everything" command will remove all historical records
128 from the filesystem. The long keyword is designed to prevent accidental use.
129 This option is not recommended.
131 Example: "hammer prune /mnt from 1h to 1d every 30m"
135 Exit status is 0 on success and 1 on error.
141 utility first appeared in
144 .An Matthew Dillon Aq dillon@backplane.com