1 bdf5b5cd 2005-07-13 devnull .TH VENTI-BACKUP 8
3 bdf5b5cd 2005-07-13 devnull rdarena, wrarena \- copy arenas between venti servers
4 bdf5b5cd 2005-07-13 devnull .SH SYNOPSIS
6 bdf5b5cd 2005-07-13 devnull .B venti/rdarena
10 bdf5b5cd 2005-07-13 devnull .I arenapart
11 bdf5b5cd 2005-07-13 devnull .I arenaname
13 bdf5b5cd 2005-07-13 devnull .B venti/wrarena
16 bdf5b5cd 2005-07-13 devnull .I fileoffset
22 bdf5b5cd 2005-07-13 devnull .I arenafile
24 bdf5b5cd 2005-07-13 devnull .I clumpoffset
26 bdf5b5cd 2005-07-13 devnull .SH DESCRIPTION
28 bdf5b5cd 2005-07-13 devnull .I Rdarena
29 bdf5b5cd 2005-07-13 devnull extracts the named
31 bdf5b5cd 2005-07-13 devnull from the arena partition
32 bdf5b5cd 2005-07-13 devnull .I arenapart
33 bdf5b5cd 2005-07-13 devnull and writes this arena to standard output.
34 bdf5b5cd 2005-07-13 devnull This command is typically used to back up an arena to external media.
37 bdf5b5cd 2005-07-13 devnull option generates more verbose output on standard error.
39 bdf5b5cd 2005-07-13 devnull .I Wrarena
40 bdf5b5cd 2005-07-13 devnull writes the blocks contained in the arena
41 bdf5b5cd 2005-07-13 devnull .I arenafile
42 bdf5b5cd 2005-07-13 devnull (typically, the output of
43 bdf5b5cd 2005-07-13 devnull .IR rdarena )
44 bdf5b5cd 2005-07-13 devnull to a Venti server.
45 bdf5b5cd 2005-07-13 devnull It is typically used to reinitialize a Venti server from backups of the arenas.
46 bdf5b5cd 2005-07-13 devnull For example,
49 bdf5b5cd 2005-07-13 devnull venti/rdarena /dev/sdC0/arenas arena.0 >external.media
50 bdf5b5cd 2005-07-13 devnull venti/wrarena -h venti2 external.media
53 bdf5b5cd 2005-07-13 devnull writes the blocks contained in
54 bdf5b5cd 2005-07-13 devnull .B arena.0
55 bdf5b5cd 2005-07-13 devnull to the Venti server
56 bdf5b5cd 2005-07-13 devnull .B venti2
57 bdf5b5cd 2005-07-13 devnull (typically not the one using
58 bdf5b5cd 2005-07-13 devnull .BR /dev/sdC0/arenas ).
62 bdf5b5cd 2005-07-13 devnull option specifies that the arena starts at byte
63 bdf5b5cd 2005-07-13 devnull .I fileoffset
67 bdf5b5cd 2005-07-13 devnull .I arenafile .
68 bdf5b5cd 2005-07-13 devnull This is useful for reading directly from
69 bdf5b5cd 2005-07-13 devnull the Venti arena partition:
72 bdf5b5cd 2005-07-13 devnull venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas
75 bdf5b5cd 2005-07-13 devnull (In this example, 335872 is the offset shown in the Venti
76 bdf5b5cd 2005-07-13 devnull server's index list (344064) minus one block (8192).
77 bdf5b5cd 2005-07-13 devnull You will need to substitute your own arena offsets
78 bdf5b5cd 2005-07-13 devnull and block size.)
80 bdf5b5cd 2005-07-13 devnull Finally, the optional
81 bdf5b5cd 2005-07-13 devnull .I offset
82 bdf5b5cd 2005-07-13 devnull argument specifies that the writing should begin with the
83 bdf5b5cd 2005-07-13 devnull clump starting at
84 bdf5b5cd 2005-07-13 devnull .I offset
85 bdf5b5cd 2005-07-13 devnull within the arena.
86 bdf5b5cd 2005-07-13 devnull .I Wrarena
87 bdf5b5cd 2005-07-13 devnull prints the offset it stopped at (because there were no more data blocks).
88 bdf5b5cd 2005-07-13 devnull This could be used to incrementally back up a Venti server
89 bdf5b5cd 2005-07-13 devnull to another Venti server:
92 bdf5b5cd 2005-07-13 devnull last=`{cat last}
93 bdf5b5cd 2005-07-13 devnull venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas $last >output
94 bdf5b5cd 2005-07-13 devnull awk '/^end offset/ { print $3 }' offset >last
97 bdf5b5cd 2005-07-13 devnull Of course, one would need to add wrapper code to keep track
98 bdf5b5cd 2005-07-13 devnull of which arenas have been processed.
100 bdf5b5cd 2005-07-13 devnull .B /sys/src/cmd/venti/backup.example
101 bdf5b5cd 2005-07-13 devnull for a version that does this.
102 bdf5b5cd 2005-07-13 devnull .SH SOURCE
103 bdf5b5cd 2005-07-13 devnull .B \*9/src/cmd/venti/srv
104 bdf5b5cd 2005-07-13 devnull .SH SEE ALSO
105 bdf5b5cd 2005-07-13 devnull .IR venti (7),
106 bdf5b5cd 2005-07-13 devnull .IR venti (8)
