We often transfer large number and large size files over the network from one computer to another. FTP is the default choice for\u00a0 transferring few files and SCP is the typical choice for transferring large number of files.<\/p>\n
If you happen to transfer files from one computer to another over a slow network(such as copying files from home computer to office or vice versa) then the following tip might be helpful. This technique works as follows:
\n1) Performs on-the-fly compression of files at source computer.
\n2) Transfer the compressed files over the network.
\n3) Performs on-the-fly decompression of the files at the target computer.
\nThis technique uses just SSH and TAR commands without creating any temporary files.<\/p>\n
Example<\/strong><\/span> 2) Command with on-the-fly compression<\/span><\/em> Let us take a\u00a0 look at this command in detail:
\nLet us assume source computer as HostA and target computer as HostB. We need to transfer a directory (\/data\/files\/) with large number of files from HostA to HostB.
\n1)<\/em> Command without on-the-fly compression<\/em><\/span>
\nRun this command on HostB
\n # scp -r HostA:\/data\/files \/tmp\/
\n<\/em>This command recursively copies \/data\/files directory from HostA to HostB<\/p>\n
\nRun this command from on HostB
\n # ssh HostA \u201ccd \/data\/;tar zcf \u2013 files\u201d | tar\u00a0 zxf \u2013
\n<\/em>This command recursively copies \/data\/files from HostA to HostB a lot faster on slow network.<\/p>\n
\n1) ssh HostA <\/strong>\u201ccd \/data\/;tar zcf \u2013 files\u201d | tar\u00a0 zxf \u2013\u00a0 :<\/em> From HostB connect to HostA via SSH.
\n2) ssh HostA \u201ccd \/data\/<\/strong>;tar zcf \u2013 files\u201d | tar\u00a0 zxf \u2013\u00a0 : <\/em>On HostA switch to directory \/data\/
\n3) ssh HostA \u201ccd \/data\/;tar zcf \u2013 files<\/strong>\u201d | tar\u00a0 zxf \u2013 : <\/em>Tar \u2018files\u2019 directory with compression and send the output to STDOUT.
\n4) ssh HostA \u201ccd \/data\/;tar zcf \u2013 files\u201d <\/em>|<\/strong> tar\u00a0 zxf \u2013 : <\/em>Pipe(|) STDOUT from HostA to STDIN of HostB.
\n5) ssh HostA \u201ccd \/data\/;tar zcf \u2013 files\u201d | tar\u00a0 zxf \u2013 <\/strong>: <\/em>On HostB decompress and untar data coming in through STDIN.<\/p>\n