GopherProxy

	tventi-backup.8 - plan9port - [fork] Plan 9 from user space
	git clone git://src.adamsgaard.dk/plan9port
	Log
	Files
	Refs
	README
	LICENSE
	---
	tventi-backup.8 (2290B)
	---
	1 .TH VENTI-BACKUP 8
	2 .SH NAME
	3 rdarena, wrarena \- copy arenas between venti servers
	4 .SH SYNOPSIS
	5 .PP
	6 .B venti/rdarena
	7 [
	8 .B -qv
	9 ]
	10 .I arenapart
	11 .I arenaname
	12 .PP
	13 .B venti/wrarena
	14 [
	15 .B -o
	16 .I fileoffset
	17 ]
	18 [
	19 .B -h
	20 .I host
	21 ]
	22 .I arenafile
	23 [
	24 .I clumpoffset
	25 ]
	26 .SH DESCRIPTION
	27 .PP
	28 .I Rdarena
	29 extracts the named
	30 .I arena
	31 from the arena partition
	32 .I arenapart
	33 and writes this arena to standard output.
	34 This command is typically used to back up an arena to external media.
	35 The
	36 .B -v
	37 option generates more verbose output on standard error;
	38 .B -q
	39 generates only errors on standard error.
	40 .PP
	41 .I Wrarena
	42 writes the blocks contained in the arena
	43 .I arenafile
	44 (typically, the output of
	45 .IR rdarena )
	46 to a Venti server.
	47 It is typically used to reinitialize a Venti server from backups of the …
	48 For example,
	49 .IP
	50 .EX
	51 venti/rdarena /dev/sdC0/arenas arena.0 >external.media
	52 venti/wrarena -h venti2 external.media
	53 .EE
	54 .LP
	55 writes the blocks contained in
	56 .B arena.0
	57 to the Venti server
	58 .B venti2
	59 (typically not the one using
	60 .BR /dev/sdC0/arenas ).
	61 .PP
	62 The
	63 .B -o
	64 option specifies that the arena starts at byte
	65 .I fileoffset
	66 (default
	67 .BR 0 )
	68 in
	69 .I arenafile .
	70 This is useful for reading directly from
	71 the Venti arena partition:
	72 .IP
	73 .EX
	74 venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas
	75 .EE
	76 .LP
	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
	80 and block size.)
	81 .PP
	82 Finally, the optional
	83 .I offset
	84 argument specifies that the writing should begin with the
	85 clump starting at
	86 .I offset
	87 within the arena.
	88 .I Wrarena
	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:
	92 .IP
	93 .EX
	94 last=`{cat last}
	95 venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas $last >output
	96 awk '/^end offset/ { print $3 }' offset >last
	97 .EE
	98 .LP
	99 Of course, one would need to add wrapper code to keep track
	100 of which arenas have been processed.
	101 See
	102 .B /sys/src/cmd/venti/words/backup.example
	103 for a version that does this.
	104 .SH SOURCE
	105 .B \*9/src/cmd/venti/srv
	106 .SH SEE ALSO
	107 .MR venti (7) ,
	108 .MR venti (8)
	109 .SH BUGS
	110 .I Wrarena
	111 can't read a pipe or network connection containing an arena;
	112 it needs a file already containing the entire arena.