AdministrativeTasks
2-30 OperatingTasks 600716 Rev A
DataMigration
A migration directory is controlled by FileServ(for example, a
directory that has a DataClass association.) Files stored under
this directory, as well as any subsequent subdirectories, are
migrated from disk to media as specified by the DataClass
parameters.
A DataClass group can be created sothat files of associated
directories exhibit certain distinctive migration behavior. These
behaviors are controlled by a combination of setting the:
• File Cleanup.
• Minimum Time parameters.
• Policies.
These are described below.
File Cleanup After a file is copied to media (migrated), the disk copy of the
file remains or is removed from the disk. The fschfiat-e
command allows a file to remain on the disk indefinitely.
The file retention for the DataClass group definition defines
how a disk copy is removed. By setting this parameter to
immediate, after a file is known to contain the required number
of copies on media, the disk copy is immediately removed. By
setting the parameter to “policy application”, the file
remains on disk even after the required number of media copies
exist.
The amount of time the file remains on disk after storage is
partially determined by setting the DataClass Minimum Time
Parameter (mintime). As long as the file system contains
empty disk space (as set by the LOBLK_THRESHOLD in the
fs_sysparm file on SGI systems), the file remains on disk
until the Minimum Time interval passes.