Tape archive system at BNL leverages the Lustre file system, mounted
at /sdcc/lustre01/lqcd/archive/.
After some time set by the migration policy, the files written to Lustre will be written to tape.
Both copying to Lustre and retrieval from tape is done by 'cp' command, similar to
regular disk file copies, except for the time delay to mount the tape.
For the 2019-2020 allocation year, USQCD has access to 600 TBytes of tape storage on this system. This USQCD storage is apportioned between users by the USQCD SPC. The USQCD Liaison helps to allocate and adjust storage for users during the allocation year, as their needs vary.
The policy governing the tape archive system are:
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Users should request creation and/or access to the project directory in the archive by filing a ticket at
SDCC. Please include the names of the project and the PI in the ticket.
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Files written to Lustre should be larger than 100 MBytes. If you have
smaller files, please tar them up. If LQCD users write files smaller
than this, the access time to restore files from tape will be large,
due to time spent seeking for small files on the tape drives.
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Users are responsible for monitoring how much space you have used in the tape archive. To
see the total space you have used on the tape archive, use "du
–apparent-size". A simple du will only show how much size the
metadata is using on Lustre, and not the total file size of the
archived files.
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It is strongly recommended to not rename or change files after they are written. Doing so will likely
cause lost storage space. Please be thoughtful about what you put on tape.