TAPING YOUR DATA

Once you have acquired your data you need to get the data home. Although you can choose to ftp your data home, it is recommended that you have a hard copy of the data by recording it to your favorite type of tape (Exabyte, Dat, DLT).
See Nigel Sharp's message on exabyte drives here.
The tape drives in the 0.9m are physically located in the computer room - each labelled with their IRAF and Unix names.
Typing devices in an IRAF (Data Reduction) window will produce a list of all the available tape drives with corresponding IRAF and Unix names.

cl> devices
 
Dome Computer IRAF Name Unix Name Description
36inch driftwood mta /dev/rmt/5bn Exabyte Eliant 820
mtacomp /dev/rmt/5cbn Exabyte - compressed
mtb /dev/rmt/6bn Exabyte Eliant 820
mtbcomp /dev/rmt/6cbn Exabyte - compressed
mtchi (mtc) /dev/rmt/2hbn DLT7000 - 35Gb
mtclo /dev/rmt/2lbn DLT7000 - 20Gb
mtccomp /dev/rmt/2ubn DLT7000 - compressed
mtz /dev/rmt/9bn DAT DDS-4
mtzcomp /dev/rmt/9cbn DAT DDS-4 - compressed
36inch Taupe mta /dev/nrst8 Exabyte 8705
mta8500c /dev/nrst16 8705 - compressed
mtb /dev/nrsx2 Exabyte 8200
mtc /dev/nrst3 Seagate Dat

Taping your MOSAIC data

 Recording your data to tape consists of allocating the tape drive and using MSCWFITS to write the Mosaic format files to
 a FITS format tape.  Every exposure produces 135 Mbytes of raw data, and so, after a good night, an observer may have
 100 images, or 13.5 Gbytes of data. Writing this volume of bits consumes a great deal of time and tape, comparable to more
 than 5 hours and 3 Exabyte 8505 tapes (possibly only 2 tapes if compression is used).  We offer a DLT-7000 tape drive at
 the 0.9-m. The DLT-7000 can write tapes about 3 times faster than the Exabyte 8505 and the tape cartridge holds 7 times
 the data volume. While tape cartridges cost about $80, they can hold roughly 3 nights of data.  As an alternative, we
 also offer two Exabyte 8505-compatible (actually, Eliant 820) drives at both telescopes.
**Remember to bring plenty of tapes for the duration of your observing run.

Taping your S2KB data

You can record your data by either using the IRAF wfits task or the Unix tar task

IRAF
In the IRAF Data Reduction window:

Allocate the appropriate drive
  allocate mtccomp (or mtb, etc...)
Write your data to tape with the wfits task
  wfits dflat*.fits mtccomp yes
   - The "yes" parameter indicates a blank tape. Alternatively you can type "no" to indicate a non-blank tape.
The cl> prompt will return when the data has been written.
Before leaving with your tape, make sure that all of your data has been written to tape.
  rfits mtccomp 1-999 make-- short+ old+
Rewind your tape (never do this manually!)
  rewmtccomp
Deallocate the drive
  deallocate mtccomp

UNIX

You need to allocate the appropriate drive in the IRAF Data Reduction window
  allocate mtccomp (or mtb, etc...)

In a Unix xterm or xgterm window:

Write your data to tape with the tar task
  tar -cvf /dev/rmt/2ubn dflat*.fits
To list the files on a tape type
   tar -tvf /dev/rmt/2ubn
Rewind the tape with
  tar -f /dev/rmt/2ubn
Deallocate the drive
  From the IRAF window type deallocate mtccomp