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As your requirements change, you can increase or decrease the sizes of the database and recovery log. You can automate the process of increasing the sizes, or you can perform all the steps manually. See Automating the Increase of the Database or Recovery Log or Manually Increasing the Database or Recovery Log.
Attention: Do not change the size of an allocated database or recovery log volume after it has been defined. If you change the size of a volume, Tivoli Storage Manager may not initialize correctly, and data may be lost.
You can automate the process of increasing the database and recovery log sizes. With a DEFINE SPACETRIGGER command, you can specify the following:
For example, assume that you have a 100GB database and a 3GB recovery log. You want to increase the database size by 25 percent when 85 percent is in use, but not to more than 200GB. You also want to increase the recovery log size by 30 percent when 75 percent is in use, but not to more than 5GB.
define spacetrigger db fullpct=85 spaceexpansion=25 expansionprefix=/usr/lpp/adsmserv/bin/ maximumsize=200000 define spacetrigger log fullpct=75 spaceexpansion=30 expansionprefix=/usr/lpp/adsmserv/bin/ maximumsize=50000
The server then monitors the database or recovery log and, if the utilization level is reached, does the following:
Notes:
Also, deleting database volumes and reducing the database does not activate the trigger. Therefore, the utilization percentage can exceed the set value before new volumes are online.
If the log mode is set to ROLLFORWARD and either the recovery log is too small or the database backup trigger is set too high, the recovery log could run out of space before database operations complete. If this happens, you may need to stop the server without enough recovery log space to restart the server. In some cases, the server halts itself.
To restart the server, first format a new volume (see Using the DSMFMT Command to Format Volumes). Then use the DSMSERV EXTEND LOG command to extend the size of the recovery log. For example, after formatting a 21MB volume named new.reclog, extend the recovery log by issuing the following command:
dsmserv extend log new.reclog 20
After the server is running, you can do the following:
To add space to the database or recovery log, do the following:
You can allocate space and define a database or recovery log volume in a single operation. For example, to allocate a 100MB database volume named VOL5 in the /usr/lpp/adsmserv/bin directory and define the volume, enter:
define dbvolume /usr/lpp/adsmserv/bin/vol5 formatsize=100
The available space of the database increases to 196MB, but the assigned capacity remains at 96MB. For Tivoli Storage Manager to use the space, you must extend the capacity (see Step 2: Extending the Capacity of the Database or Recovery Log). To verify the change, query the database or recovery log. For example, to query the database, enter:
query db
The server displays a report, like this:
+--------------------------------------------------------------------------------+ |Available Assigned Maximum Maximum Page Total Used %Util Max. | | Space Capacity Extension Reduction Size Pages Pages %Util | | (MB) (MB) (MB) (MB) (bytes) | |--------- -------- --------- --------- ------- --------- --------- ----- ----- | | 196 96 100 92 4,096 24,576 86 0.3 0.3 | +--------------------------------------------------------------------------------+
The value in the Maximum Extension field should equal the available space of the new volume. In this example, a 101MB volume was allocated. This report shows that the available space has increased by 100MB; the assigned capacity is unchanged at 96MB; and the maximum extension is 100MB. Figure 56 illustrates these changes.
Figure 56. Adding Volumes Increases Available Space
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You can also query the database and recovery log volumes to display information about the physical volumes that make up the database and recovery log.
Notes:
If you already have a number of small volumes and want to consolidate the space into one large volume, see Decreasing the Size of the Database or Recovery Log.
You can still use the DSMFMT utility to allocate a database or recovery log volume. You would then issue the DEFINE DBVOLUME or DEFINE LOGVOLUME command without the FORMATSIZE parameter, and extend the database or recovery log (see Step 2: Extending the Capacity of the Database or Recovery Log).
To allocate an additional 101MB to the database as volume VOL5, enter:
> dsmfmt -db vol5 101
The database and recovery log are extended in 4MB increments. If you do not specify the extension in 4MB increments, the server rounds up to the next 4MB partition. For example, if you specify 1MB, the server extends the capacity by 4MB.
To increase the capacity of the database by 100MB, enter:
extend db 100
After the database has been extended, the available space and assigned capacity are both equal to 196MB, as shown in Figure 57.
Figure 57. Extending the Capacity of the Database
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You can query the database or recovery log (QUERY DB and QUERY LOG commands) to verify their assigned capacities. The server would display a report, like this:
+--------------------------------------------------------------------------------+ |Available Assigned Maximum Maximum Page Total Used %Util Max. | | Space Capacity Extension Reduction Size Pages Pages %Util | | (MB) (MB) (MB) (MB) (bytes) | |--------- -------- --------- --------- ------- --------- --------- ----- ----- | | 196 196 0 192 4,096 50,176 111 0.2 0.2 | +--------------------------------------------------------------------------------+