1dccp(1) General Commands Manual dccp(1)
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6 dccp - Copy a file from or to a dCache server.
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10 dccp [option...] <sourceUrl> <destUrl>
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14 The following arguments are required:
15 sourceUrl
17 The URL of the source file.
19 destUrl
21 The URL of the destination file.
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26 The dccp utility provides a cp(1) like functionality on the dCache file
27 system. The source must be a single file while the destination could be
28 a directory name or a file name. If the directory is a destination, a
29 new file with the same name as the source name will be created there
30 and the contents of the source will be copied. If the final destination
31 file exists in dCache, it won’t be overwritten and an error code will
32 be returned. Files in regular file systems will always be overwritten
33 if the -i option is not specified. If the source and the final destina‐
34 tion file are located on a regular file system, the dccp utility can be
35 used similar to the cp(1) program.
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39 The following arguments are optional:
40 -a
42 Enable read-ahead functionality.
43 -b <bufferSize>
45 Set read-ahead buffer size. The default value is 1048570 Bytes.
47 To disable the buffer this can be set to any value below the
48 default. dccp will attempt to allocate the buffer size so very
49 large values should be used with care.
50 -B <bufferSize>
52 Set buffer size. The size of the buffer is requested in each
54 request, larger buffers will be needed to saturate higher band‐
55 width connections. The optimum value is network dependent. Too
56 large a value will lead to excessive memory usage, too small a
57 value will lead to excessive network communication.
58 -d <debug level>
60 Set the debug level. <debug level> is a integer between 0 and
62 127. If the value is 0 then no output is generated, otherwise
63 the value is formed by adding together one or more of the fol‐
64 lowing values:
65 Value Enabled output
67 1 Error messages
68 2 Info messages
69 4 Timing information
70 8 Trace information
71 16 Show stack-trace
72 32 IO operations
73 32 IO operations
74 64 Thread information
75 -h <replyHostName>
77 Bind the callback connection to the specific hostname interface.
79 -H
81 show progress during file transfer.
83 -i
85 Secure mode. Do not overwrite the existing files.
87 -l <location>
89 Set location for pre-stage. if the location is not specified,
91 the local host of the door will be used. This option must be
92 used with the -P option.
93 -p <first_port>:<last_port>
95 Bind the callback data connection to the specified TCP
97 port/rangeSet port range. Delimited by the ’:’ character, the
98 <first_port> is required but the <last_port> is optional.
99 -P
101 Pre-stage. Do not copy the file to a local host but make sure
103 the file is on disk on the dCache server.
104 -r <bufferSize>
106 TCP receive buffer size. The default is 256K. Setting to 0 uses
108 the system default value. Memory useage will increase with
109 higher values, but performance better.
110 -s <bufferSize>
112 TCP send buffer size. The default is 256K. Setting to 0 uses the
114 system default value.
115 -t <time>
117 Stage timeout in seconds. This option must be used with the -P
119 option.
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123 To copy a file to dCache:
124 [user] $ dccp /etc/group dcap://example.org/pnfs/desy.de/gading/
126 To copy a file from dCache:
128 [user] $ dccp dcap://example.org/pnfs/desy.de/gading/group /tmp/
130 Pre-Stage request:
132 [user] $ dccp -P -t 3600 -l example.org
134 /acs/user_space/data_file
135 stdin:
137 [user] $ tar cf - data_dir | dccp -
139 /acs/user_space/data_arch.tar
140 stdout:
142 [user] $ dccp /acs/user_space/data_arch.tar - | tar xf -
144
147 cp
148version 2.47.6 22 February 2011 dccp(1)