Writing images to exabyte or DAT tape can be done with the IRAF task wfits. Recall that the raw NIRIM data are in fits format, even though they do not have a “.fits” extension. We recommend that you use wfits only if you have either renamed all the files to have a “.fits” extension and/or have run the nproc task. In order to make a tape:
· cl> allocate devicename
· cl> wfits filenames devicename yes/no
Where the yes/no response is to answer if the tape is new. There are many other options available and they can be perused in the epar wfits task. Device names for sand are mta for the Exabyte drive, and mtb for the DAT drive. The DAT supports DDS-4 densities (20 Gbytes per tape). The DAT on sand is internal to the tower box while the Exabyte is external. On pearl, the Exabyte is mtb and the DAT is mtc. The DAT on pearl, though, only supports densities to DDS-2. Both drives on pearl are external, and networking access to pearl requires the IRAF device name would actually be pearl!mtb or pearl!mtc.
In order to check to see what is on the tape, you can list the titles quite easily. Simply do a
· cl> rfits devicename 1-999 list+ short+ original+
in order to see what's there. To direct this output into a file, you can add a ‘> tapelist’ to the end, and then you can print that list on the lineprinter by a simple ‘lprint tapelist’.
NOTE: If you do write additional files to an “old tape” (one containing useful data but which had previously been removed from the drive), make certain that the software (IRAF and Unix) is aware that the tape has been rewound before starting to write to the tape----or your old data may be overwritten! To safeguard against this possibility we suggest that you ALWAYS swap tapes by first:
· cl> deallocate devicename
Physically swap tapes
· cl> allocate devicename