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4. How to strip the data?

We are goind to strip 2 million events from the tapes we have just selected.

First, make sure that there is enough disk space available. The rule of thumb is that 2 million .dst and .cal events will take about 2 Gbytes of disk space and 5000 .mst events will take about 100 Mbytes of disk space in the mst directory.

At BNL we are using two disks: /s/s12/e852/lgd_1995 and /s/s4/e852/lgd_1995. All the .mst files are stored on /s/s12. Normally /s/s4 has 4 Gbytes and /s/s12 3 Gbytes of free space.

Now that we have disk space, we can start the stripping. Multiple stripping jobs can run at the same time. Mount the input tape on a tape drive and run:

strip-1995 -E -g12021 < /dev/dlt2v

here '-E' tells the program to eject the tape at the end, '-g12021' tells the program to ignore all data that is not part of group 12021, '< /dev/dlt2v' redirects the standard input from the tape device with the input tape.

To strip the whole tape (not just one group), omit the -g switch.

To strip only the monitoring data (only .mst files), specify the '-B' switch.

It takes about 2-3 hours to strip 2 Mevents from a typical DLT-2000 tape.

After the stripper is done, the following files and directories will be created:


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