Hierarchical Storage Management (HSM) |
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Please
read the details of a plan to automatically shelve old
files on the SLD |
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| HSM
allows users to 'shelve' files. Shelving copies a file's
data from disk to tape and deletes the data on disk,
while retaining the file-header. After shelving, the zero in the "size" field shows that the file is no longer on disk. Accordingly, the file counts zero blocks against the user quota. The user is able to issue commands such as DIR and SET FILE, however, an attempts to read the file causes HSM to move the file from tape back onto the disk. While this can require a significant amount of time, the work of HSM is transparent to the user or application. |
Example
of shelving a file with HSM $ DIR/SIZ=ALL/SHELVE ACCOUNTING.DAT Directory SYS$LOC_ROOT:[SYSMGR]
Total of 1 file, 8513/8520 blocks. $ SHELVE/NOWAIT ACCOUNTING.DAT $ DIR/SIZ=ALL/SHELVE ACCOUNTING.DAT Directory SYS$LOC_ROOT:[SYSMGR]
Total of 1 file, 8513/0 blocks. |
Author: wendling@slac.stanford.edu