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VENTI-BACKUP(8)		    System Manager's Manual	       VENTI-BACKUP(8)

NAME
       rdarena,	wrarena	- copy arenas between venti servers

SYNOPSIS
       venti/rdarena [ -qv ] arenapart arenaname

       venti/wrarena [ -o fileoffset ] [ -h host ] arenafile [ clumpoffset ]

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,

	      venti/rdarena /dev/sdC0/arenas arena.0 >external.media
	      venti/wrarena -h venti2 external.media

       writes the blocks contained in arena.0 to the Venti server venti2 (typ-
       ically not the one using	/dev/sdC0/arenas).

       The -o option specifies that the	arena starts at	byte  fileoffset  (de-
       fault  0)  in arenafile .  This is useful for reading directly from the
       Venti arena partition:

	      venti/wrarena -h venti2 -o 335872	/dev/sdC0/arenas

       (In this	example, 335872	is the offset shown in the Venti server's  in-
       dex  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:

	      last=`{cat last}
	      venti/wrarena -h venti2 -o 335872	/dev/sdC0/arenas $last >output
	      awk '/^end offset/ { print $3 }' offset >last

       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.exam-
       ple for a version that does this.

SOURCE
       /usr/local/plan9/src/cmd/venti/srv

SEE ALSO
       venti(7), venti(8)

BUGS
       Wrarena can't read a pipe or network connection containing an arena; it
       needs a file already containing the entire arena.

							       VENTI-BACKUP(8)

NAME | SYNOPSIS | DESCRIPTION | SOURCE | SEE ALSO | BUGS

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