3 rdarena, wrarena \- copy arenas between venti servers
31 from the arena partition
33 and writes this arena to standard output.
34 This command is typically used to back up an arena to external media.
37 option generates more verbose output on standard error.
40 writes the blocks contained in the arena
42 (typically, the output of
45 It is typically used to reinitialize a Venti server from backups of the arenas.
49 venti/rdarena /dev/sdC0/arenas arena.0 >external.media
50 venti/wrarena -h venti2 external.media
53 writes the blocks contained in
57 (typically not the one using
58 .BR /dev/sdC0/arenas ).
62 option specifies that the arena starts at byte
68 This is useful for reading directly from
69 the Venti arena partition:
72 venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas
75 (In this example, 335872 is the offset shown in the Venti
76 server's index list (344064) minus one block (8192).
77 You will need to substitute your own arena offsets
82 argument specifies that the writing should begin with the
87 prints the offset it stopped at (because there were no more data blocks).
88 This could be used to incrementally back up a Venti server
89 to another Venti server:
93 venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas $last >output
94 awk '/^end offset/ { print $3 }' offset >last
97 Of course, one would need to add wrapper code to keep track
98 of which arenas have been processed.
100 .B /sys/src/cmd/venti/backup.example
101 for a version that does this.
103 .B \*9/src/cmd/venti/srv