IBM E16RMLL-I - Tivoli Storage Manager, Руководство по внедрению

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Chapter 7. Data storage policies
275
Directory expiration should be governed by a separate management class. The
backup copy group retention options for both existing versions and deleted
versions for this management class should be set so that the directory objects do
not expire before the files beneath them in the directory tree. In our case, we
allow an unlimited number of directory objects to be stored within the Tivoli
Storage Manager repository for as long as a file object associated with a
directory exists in the repository. In other words, we set directory object
expiration at least as long as the longest retention for the files. It is all right to
store an unlimited number of directory objects, since they occupy insignificant
space within the Tivoli Storage Manager server repository as compared to file
and other objects. This will ensure that your clients can perform point-in-time
restores within the defined expiration period.
The SERIALIZATION parameter also illustrates the difference between the
management classes. The backup copy group for the
special
management class
is set up to use the serialization parameter of SHRDYNAMIC instead of
SHRSTATIC. Log files and other files where the files are always open, but that
we nevertheless want to back up, should be bound to this management class.
In Example 7-4 we define the backup copy group for each of the management
classes, using
define copygroup
command.
Example 7-4 Defining backup copy group
tsm: ATLANTIC>
define copygroup server server data type=Backup
destination=DISKDATA frequency=1 verexists=3 verdeleted=1 retextra=100 retonly=100
mode=modified serialization=shrstatic
ANR1530I Backup copy group STANDARD defined in policy domain SERVER, set
SERVER, management class DATA.
tsm: ATLANTIC>
define copygroup server server directory type=Backup
Note: For expiration control of image backups, versions deleted (VERDEL)
and retain only (RETONLY) settings do not apply. Image backups are
controlled by the VEREXIST and RETEXTRA options only. Nevertheless, in
our example we set the values of retver/retonly verexist/verdel the same for
both
image
management classes to avoid confusion.
Tip: If some of your data require policy settings different than our
recommended defaults (for example, if you need to keep seven copy versions
of certain files), then you need to create an additional management class for
this purpose, and assign the data to it using the INCLUDE option. See
“Options file” on page 114 for further information.