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;
39 generates only errors on standard error.
42 writes the blocks contained in the arena
44 (typically, the output of
47 It is typically used to reinitialize a Venti server from backups of the arenas.
51 venti/rdarena /dev/sdC0/arenas arena.0 >external.media
52 venti/wrarena -h venti2 external.media
55 writes the blocks contained in
59 (typically not the one using
60 .BR /dev/sdC0/arenas ).
64 option specifies that the arena starts at byte
70 This is useful for reading directly from
71 the Venti arena partition:
74 venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas
77 (In this example, 335872 is the offset shown in the Venti
78 server's index list (344064) minus one block (8192).
79 You will need to substitute your own arena offsets
84 argument specifies that the writing should begin with the
89 prints the offset it stopped at (because there were no more data blocks).
90 This could be used to incrementally back up a Venti server
91 to another Venti server:
95 venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas $last >output
96 awk '/^end offset/ { print $3 }' offset >last
99 Of course, one would need to add wrapper code to keep track
100 of which arenas have been processed.
102 .B /sys/src/cmd/venti/words/backup.example
103 for a version that does this.
105 .B \*9/src/cmd/venti/srv
111 can't read a pipe or network connection containing an arena;
112 it needs a file already containing the entire arena.