|  | 
 NAME     
 |  |  |  | rdarena, wrarena – copy arenas between venti servers 
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 SYNOPSIS     
 |  |  |  | venti/rdarena [ −qv ] arenapart arenaname 
    
    
    venti/wrarena [ −o fileoffset ] [ −h host ] arenafile [ clumpoffset
    ] 
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 DESCRIPTION     
 |  |  |  | Rdarena extracts the named arena from the arena partition arenapart
    and writes this arena to standard output. This command is typically
    used to back up an arena to external media. The −v option generates
    more verbose output on standard error; −q generates only errors
    on standard error. 
    
    
    Wrarena writes the blocks contained in the arena arenafile (typically,
    the output of rdarena) to a Venti server. It is typically used
    to reinitialize a Venti server from backups of the arenas. For
    example, 
 writes the blocks contained in arena.0 to the Venti server venti2
    (typically not the one using /dev/sdC0/arenas). 
    
    
    The −o option specifies that the arena starts at byte fileoffset
    (default 0) in arenafile . This is useful for reading directly
    from the Venti arena partition:|  |  |  | venti/rdarena /dev/sdC0/arenas arena.0 >external.media venti/wrarena −h venti2 external.media
 
 | 
 
 (In this example, 335872 is the offset shown in the Venti server’s
    index list (344064) minus one block (8192). You will need to substitute
    your own arena offsets and block size.) 
    
    
    Finally, the optional offset argument specifies that the writing
    should begin with the clump starting at offset within the arena.
    Wrarena prints the offset it stopped at (because there were no
    more data blocks). This could be used to incrementally back up
    a Venti server to another Venti server:|  |  |  | venti/wrarena −h venti2 −o 335872 /dev/sdC0/arenas 
 | 
 
 Of course, one would need to add wrapper code to keep track of
    which arenas have been processed. See /sys/src/cmd/venti/words/backup.example
    for a version that does this.|  |  |  | last=`{cat last} venti/wrarena −h venti2 −o 335872 /dev/sdC0/arenas $last >output
 awk '/^end offset/ { print $3 }' offset >last
 
 | 
 
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 SOURCE     
 SEE ALSO    
 BUGS     
 |  |  |  | Wrarena can’t read a pipe or network connection containing an
    arena; it needs a file already containing the entire arena. 
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