File Devclass reported with a "warning" on Operations Center

Problem
Some FILE device classes may be shown with a critical status on Operations Center without a clear
reason.

Cause
By default the critical status for a FILE device class is displayed if the remaining space on the filesystem(s) defined in the device class, cannot fulfil 50% or more of the potential scratch volumes needed.

Diagnosing the problem
To verify the current settings for the FILE device class status monitoring thresholds use the following command from Tivoli Storage Manager Server Administrative Command Line (dsmadmc):

query statusthreshold def_file*

The command will return an output like the following:

Threshold Name: DEF_FILEDEVCLASSPCTSCRUNALLOCATABLE_E
Activity Name : NON-SHARED FILE DEV PERCENTAGE SCRATCH VOLUMES
UNALLOCATABLE
Condition Name: >=
Value: 50
Report Status: ERROR
Server Name: TSMSERVER1

Threshold Name: DEF_FILEDEVCLASSPCTSCRUNALLOCATABLE_W
Activity Name : NON-SHARED FILE DEV PERCENTAGE SCRATCH VOLUMES
UNALLOCATABLE
Condition Name: >=
Value: 25
Report Status: ERROR
Server Name: TSMSERVER1

The conditions and value shown in the example above are the default ones.
To calculate if the "warning" status is appropriate, it is necessary to take into account the following parameters:

how many storage pools are associated to the FILE device class (check with the Q STGPOOL command)

how many scratch volumes are defined for each storage pool in the parameter "Maximum ScratchVolume" (check with the Q STGPOOL command)

the estimated capacity of each volumes (check with the Q DEVC command)

how many volumes are currently in use for that FILE devclass (check with the Q SYSTEM command)

the available space of the filesystem/directory associated with the FILE device class (check this with OS commands)

For example, if for a FILE Device Class called "FILEDEVC" you have 2 Storage Pools defined, each one with the MAXSCRATCH parameter set to 100 and, together, the two pools have 40 volumes in use, this means the Tivoli Storage Manager server potentially can use 160 more scratch volumes:

100 maxscratch x 2 Stgpool = 200 maxscratch - 40 volumes in use = 160 volumes

Assuming that the Estimate Capacity for each volume is 100MB, with 160 potential volumes, the Tivoli Storage Manager server could require 16000MB (~ 15.6 GB) of space if using the remaining volumes.

Considering a default setting for the FILE device class status monitoring thresholds of 50%, as in the above example, the warning message for the FILEDEVC will be shown if the available space on the filesystem associated to that, is lower or equal to the 50% of 15.6GB.

Resolving the problem
There are multiple solutions to avoid the "warning" status for FILE device classes:
- reduce the maxscratch value in the storage pool(s)
OR
- reduce the estimate capacity of the volumes to meet this 50% threshold
OR
- change the condition of the FILE device class status monitoring thresholds using this command:
UPDATE STATUSTHRESHOLD