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NAME
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read, write, copy – simple Venti clients
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SYNOPSIS
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venti/read [ −h host ] [ −t type ] score
venti/write [ −z ] [ −h host ] [ −t type ]
venti/copy [ −fir ] [ −t type ] srchost dsthost score
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DESCRIPTION
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Venti is a SHA1-addressed block storage server. See venti(7) for
a full introduction.
Read reads a block with the given score and numeric type from
the server host and prints the block to standard output. If the
−h option is omitted, read consults the environment variable $venti
for the name of the Venti server. If the −t option is omitted,
read will try each type, one at a time, until it finds one that
works. It prints the corresponding read
−t command to standard error to indicate the type of the block.
Write writes at most 56 kilobytes of data from standard input
to the server host and prints the resulting score to standard
output. If the −t option is omitted, write uses type 0, denoting
a data block. If the −z option is given, write zero truncates
the block before writing it to the server.
Copy expects score to be the score of a VtRoot block. It copies
the entire tree of blocks reachable from the root block from the
server srchost to the server dsthost.
The −f option causes copy to run in ‘fast’ mode, assuming that
if a block already exists on the destination Venti server, all
its children also exist and need not be checked.
The −i and −r option control copy’s reaction to errors reading
from srchost. Copy always prints information to standard error
about each read error. By default, copy exits after printing the
first error. If the −i option is given, read errors are ignored.
This is dangerous behavior because it breaks the assumption made
by ‘fast’ mode. If the −r option is
given, copy replaces pointers to unreadable blocks with pointers
to the zero block. It writes the new root score to standard output.
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SOURCE
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/usr/local/plan9/src/cmd/venti
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SEE ALSO
BUGS
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There should be programs to read and write venti files and directories.
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