1 bdf5b5cd 2005-07-13 devnull .TH VENTI-BACKUP 8
  2 bdf5b5cd 2005-07-13 devnull .SH NAME
  3 bdf5b5cd 2005-07-13 devnull rdarena, wrarena \- copy arenas between venti servers
  4 bdf5b5cd 2005-07-13 devnull .SH SYNOPSIS
  5 bdf5b5cd 2005-07-13 devnull .PP
  6 bdf5b5cd 2005-07-13 devnull .B venti/rdarena
  7 bdf5b5cd 2005-07-13 devnull [
  8 cbc99e3e 2011-06-03 rsc .B -qv
  9 bdf5b5cd 2005-07-13 devnull ]
 10 bdf5b5cd 2005-07-13 devnull .I arenapart
 11 bdf5b5cd 2005-07-13 devnull .I arenaname
 12 bdf5b5cd 2005-07-13 devnull .PP
 13 bdf5b5cd 2005-07-13 devnull .B venti/wrarena
 14 bdf5b5cd 2005-07-13 devnull [
 15 bdf5b5cd 2005-07-13 devnull .B -o
 16 bdf5b5cd 2005-07-13 devnull .I fileoffset
 17 bdf5b5cd 2005-07-13 devnull ]
 18 bdf5b5cd 2005-07-13 devnull [
 19 bdf5b5cd 2005-07-13 devnull .B -h
 20 bdf5b5cd 2005-07-13 devnull .I host
 21 bdf5b5cd 2005-07-13 devnull ]
 22 bdf5b5cd 2005-07-13 devnull .I arenafile
 23 bdf5b5cd 2005-07-13 devnull [
 24 bdf5b5cd 2005-07-13 devnull .I clumpoffset
 25 bdf5b5cd 2005-07-13 devnull ]
 26 bdf5b5cd 2005-07-13 devnull .SH DESCRIPTION
 27 bdf5b5cd 2005-07-13 devnull .PP
 28 bdf5b5cd 2005-07-13 devnull .I Rdarena
 29 bdf5b5cd 2005-07-13 devnull extracts the named
 30 bdf5b5cd 2005-07-13 devnull .I arena
 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.
 35 bdf5b5cd 2005-07-13 devnull The
 36 bdf5b5cd 2005-07-13 devnull .B -v
 37 cbc99e3e 2011-06-03 rsc option generates more verbose output on standard error;
 38 cbc99e3e 2011-06-03 rsc .B -q
 39 cbc99e3e 2011-06-03 rsc generates only errors on standard error.
 40 bdf5b5cd 2005-07-13 devnull .PP
 41 bdf5b5cd 2005-07-13 devnull .I Wrarena
 42 bdf5b5cd 2005-07-13 devnull writes the blocks contained in the arena
 43 bdf5b5cd 2005-07-13 devnull .I arenafile
 44 bdf5b5cd 2005-07-13 devnull (typically, the output of
 45 bdf5b5cd 2005-07-13 devnull .IR rdarena )
 46 bdf5b5cd 2005-07-13 devnull to a Venti server.
 47 bdf5b5cd 2005-07-13 devnull It is typically used to reinitialize a Venti server from backups of the arenas.
 48 bdf5b5cd 2005-07-13 devnull For example,
 49 bdf5b5cd 2005-07-13 devnull .IP
 50 bdf5b5cd 2005-07-13 devnull .EX
 51 bdf5b5cd 2005-07-13 devnull venti/rdarena /dev/sdC0/arenas arena.0 >external.media
 52 bdf5b5cd 2005-07-13 devnull venti/wrarena -h venti2 external.media
 53 bdf5b5cd 2005-07-13 devnull .EE
 54 bdf5b5cd 2005-07-13 devnull .LP
 55 bdf5b5cd 2005-07-13 devnull writes the blocks contained in
 56 bdf5b5cd 2005-07-13 devnull .B arena.0
 57 bdf5b5cd 2005-07-13 devnull to the Venti server
 58 bdf5b5cd 2005-07-13 devnull .B venti2
 59 bdf5b5cd 2005-07-13 devnull (typically not the one using
 60 bdf5b5cd 2005-07-13 devnull .BR /dev/sdC0/arenas ).
 61 bdf5b5cd 2005-07-13 devnull .PP
 62 bdf5b5cd 2005-07-13 devnull The
 63 bdf5b5cd 2005-07-13 devnull .B -o
 64 bdf5b5cd 2005-07-13 devnull option specifies that the arena starts at byte
 65 bdf5b5cd 2005-07-13 devnull .I fileoffset
 66 bdf5b5cd 2005-07-13 devnull (default
 67 bdf5b5cd 2005-07-13 devnull .BR 0 )
 68 bdf5b5cd 2005-07-13 devnull in
 69 bdf5b5cd 2005-07-13 devnull .I arenafile .
 70 bdf5b5cd 2005-07-13 devnull This is useful for reading directly from
 71 bdf5b5cd 2005-07-13 devnull the Venti arena partition:
 72 bdf5b5cd 2005-07-13 devnull .IP
 73 bdf5b5cd 2005-07-13 devnull .EX
 74 bdf5b5cd 2005-07-13 devnull venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas
 75 bdf5b5cd 2005-07-13 devnull .EE
 76 bdf5b5cd 2005-07-13 devnull .LP
 77 bdf5b5cd 2005-07-13 devnull (In this example, 335872 is the offset shown in the Venti
 78 bdf5b5cd 2005-07-13 devnull server's index list (344064) minus one block (8192).
 79 bdf5b5cd 2005-07-13 devnull You will need to substitute your own arena offsets
 80 bdf5b5cd 2005-07-13 devnull and block size.)
 81 bdf5b5cd 2005-07-13 devnull .PP
 82 bdf5b5cd 2005-07-13 devnull Finally, the optional
 83 bdf5b5cd 2005-07-13 devnull .I offset
 84 bdf5b5cd 2005-07-13 devnull argument specifies that the writing should begin with the
 85 bdf5b5cd 2005-07-13 devnull clump starting at
 86 bdf5b5cd 2005-07-13 devnull .I offset
 87 bdf5b5cd 2005-07-13 devnull within the arena.
 88 bdf5b5cd 2005-07-13 devnull .I Wrarena
 89 bdf5b5cd 2005-07-13 devnull prints the offset it stopped at (because there were no more data blocks).
 90 bdf5b5cd 2005-07-13 devnull This could be used to incrementally back up a Venti server
 91 bdf5b5cd 2005-07-13 devnull to another Venti server:
 92 bdf5b5cd 2005-07-13 devnull .IP
 93 bdf5b5cd 2005-07-13 devnull .EX
 94 bdf5b5cd 2005-07-13 devnull last=`{cat last}
 95 bdf5b5cd 2005-07-13 devnull venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas $last >output
 96 bdf5b5cd 2005-07-13 devnull awk '/^end offset/ { print $3 }' offset >last
 97 bdf5b5cd 2005-07-13 devnull .EE
 98 bdf5b5cd 2005-07-13 devnull .LP
 99 bdf5b5cd 2005-07-13 devnull Of course, one would need to add wrapper code to keep track
100 bdf5b5cd 2005-07-13 devnull of which arenas have been processed.
101 bdf5b5cd 2005-07-13 devnull See
102 cbc99e3e 2011-06-03 rsc .B /sys/src/cmd/venti/words/backup.example
103 bdf5b5cd 2005-07-13 devnull for a version that does this.
104 bdf5b5cd 2005-07-13 devnull .SH SOURCE
105 bdf5b5cd 2005-07-13 devnull .B \*9/src/cmd/venti/srv
106 bdf5b5cd 2005-07-13 devnull .SH SEE ALSO
107 d32deab1 2020-08-16 rsc .MR venti (7) ,
108 d32deab1 2020-08-16 rsc .MR venti (8)
109 cbc99e3e 2011-06-03 rsc .SH BUGS
110 cbc99e3e 2011-06-03 rsc .I Wrarena
111 cbc99e3e 2011-06-03 rsc can't read a pipe or network connection containing an arena;
112 cbc99e3e 2011-06-03 rsc it needs a file already containing the entire arena.