A1900 A1900 Fragment Separator NSCL

How to read A1900 data tapes

This document describes how to read A1900 data tapes at the NSCL. All A1900 run data is archived on DLT IV or LTO tapes in UNIX tar format. Insert the tape in one of the tape drives connected to the computer tapehost. tapehost is located in the Data-U area. The device name (/dev/st0 or /dev/st1) of the tape drive is marked on the drive.

Login to tapehost and change into the destination directory for the run data. To copy data from tape drive /dev/st0 to disc use the following command (for tapes 007 up to 012):

tar -x -v -b 128 -f /dev/st0

If you want to copy only part of the data you can specify this at the end of the tar command. The following command will copy only the archived data for run 1438:

tar -x -v -b 128 -f /dev/st0 ./run1438

Tapes with tape number 001 up to 006 were written with standard tar block sizes. It will take considerably more time to read these tapes. To read data from these tapes omit the blocking factor argument with the tar command:

tar -x -v -f /dev/st0

Tapes 013 and 014 have been written with the tar standard block size, too. The command to read these tapes is:

tar -xvf /dev/st0

For more possibilities please refer to the documentation of the tar command.

© A1900 Group, 2008-07-07