Using FTP and PFTP to access HPSS files from IU Research Systems
Access to HPSS is available via the standard internet protocol ftp, and the optimized protocol pftp. FTP is a widely used as a general means of moving files between systems. ftp can be used to access HPSS from any platform, while pftp is available only on the IU research systems. When using ftp, your user name and password must be entered manually or through the use of a user-provided ".netrc file". Please note that IU does not recommend the use of a .netrc file, for security reasons.
Traditional ftp allows both text or ("ascii") and binary (or "image") transfer modes. Most versions of ftp default to "ascii" mode; however, HPSS allows only "binary" transfers.
PFTP (Parallel FTP) is a more powerful and flexible variant of ftp which is available only on the IU research systems and clients in which the client binary has been installed. It is able to perform automatic DCE authentication, so .netrc files are not required. It is more desirable than ordinary ftp for large file transfers (> 100 MB) due to its increased performance, flexibility, and security.
PFTP provides parallel versions of data transfer commands, in addition to the standard commands of traditional ftp. In ftp, where one might use "put" or "get" to move a file, pftp also provides "pput" and "pget". Similarly, where ftp has "mput" and "mget" commands to move multiple files, pftp has "mpput" and "mpget". Other commands are identical in ftp and pftp. The following table lists a few pftp variants of ftp commands; many others are available and are documented in the ftp and pftp man pages.
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get |
retrieve a file |
pget |
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put |
store a file |
pput |
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mget |
retrieve multiple files |
mpget |
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mput |
store multiple files |
mpput |
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append |
append a local file to a remote file |
pappend |
More information regarding HPSS can be found at the DSSG web site.
