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1 .TH VENTI 12 .SH NAME3 read, write, copy \- simple Venti clients4 .SH SYNOPSIS5 .B venti/read6 [7 .B -h8 .I host9 ]10 [11 .B -t12 .I type13 ]14 .I score15 .br16 .B venti/write17 [18 .B -z19 ]20 [21 .B -h22 .I host23 ]24 [25 .B -t26 .I type27 ]28 .br29 .B venti/copy30 [31 .B -fir32 ]33 [34 .B -t35 .I type36 ]37 .I srchost38 .I dsthost39 .I score40 .SH DESCRIPTION41 Venti is a SHA1-addressed block storage server.42 See43 .IR venti (7)44 for a full introduction.45 .PP46 .I Read47 reads a block with the given48 .I score49 and numeric50 .I type51 from the server52 .I host53 and prints the block to standard output.54 If the55 .B -h56 option is omitted,57 .I read58 consults the environment variable59 .B $venti60 for the name of the Venti server.61 If the62 .B -t63 option is omitted,64 .I read65 will try each type, one at a time, until it finds66 one that works.67 It prints the corresponding68 .B read69 .B -t70 command to standard error71 to indicate the type of the block.72 .PP73 .I Write74 writes at most 56 kilobytes of data from standard input75 to the server76 .I host77 and prints the resulting score to standard output.78 If the79 .B -t80 option is omitted,81 .I write82 uses type 0,83 denoting a data block.84 If the85 .B -z86 option is given,87 .I write88 zero truncates the block before writing it to the server.89 .PP90 .I Copy91 expects92 .I score93 to be the score of a94 .B VtRoot95 block.96 It copies the entire tree of blocks reachable from97 the root block from the server98 .I srchost99 to the server100 .IR dsthost .101 .PP102 The103 .B -f104 option causes105 .I copy106 to run in `fast' mode,107 assuming that if a block already exists on the108 destination Venti server, all its children also109 exist and need not be checked.110 .PP111 The112 .B -i113 and114 .B -r115 option control116 .IR copy 's117 reaction to errors reading118 from119 .IR srchost .120 .I Copy121 always prints information to standard error122 about each read error.123 By default,124 .I copy125 exits after printing the first error.126 If the127 .B -i128 option is given, read errors are ignored.129 This is dangerous behavior because it breaks the130 assumption made by `fast' mode.131 If the132 .B -r133 option is given,134 .I copy135 replaces pointers to unreadable blocks with136 pointers to the zero block.137 It writes the new root score to standard output.138 .SH SOURCE139 .B \*9/src/cmd/venti140 .SH SEE ALSO141 .IR vac (1),142 .IR venti (3),143 .IR vacfs (4),144 .IR venti (7),145 .IR vbackup (8),146 .IR venti (8)147 .SH BUGS148 There should be programs to read and write149 venti files and directories.