Space allocation allows you to establish the maximum amount of space that must be used by the mount path. This can be done by specifying the reserve space.
The default value of reserve space during mount path creation is 2% of mount path capacity or 100GB, whicever is lower. For example:
-
If the mount path size is 10TB in total, then reserve space will be set to 100GB, because 2% of 10TB is 200GB.
-
If the mount path size is 4TB in total, then reserve space will be set to 80GB (2% of 4TB), which is lower than 100GB.
You can select either the Use until the mount path reaches the reserved space or Do not consume more than n GB options.
-
In some situations the mount path may consume more space and exceed the specified minimum reserve space. Consider the following example:
If you have established the minimum reserve space as 2 GB, and run a two-streamed data protection operation when the disk space is 2.01 GB, both the streams will use a minimum of 25 MB before spanning to an alternate mount path. In such a situation the free space will fall below the specified 2 GB.
This could also happen if two concurrent single-streamed data protection operation are initiated to the same mount path using two different storage policies.
-
Similarly, the system might consume more than the specified maximum space. Consider the following example:
When a data protection job is initiated, the system checks for the available disk space and verifies whether it is less than the specified maximum space. For example if you have specified 5 GB as the maximum space and if you have used 4.75 GB, the data protection job will be initiated using the mount path. However, if the size of the data is .5 GB, the system will write the entire data. In such a situation the space consumed will be more than the specified maximum space.
A data protection operation will generally write to the mount path until the minimum reserve space is reached, before spanning to an alternate path.
Procedure
-
From the CommCell Browser, expand to Storage Resources | Libraries | <Library>.
-
Right-click the appropriate mount path, and then click Properties.
-
Click the Allocation Policy tab.
-
In the Space Allocation section, establish one or more of the following options:
-
Specify the minimum reserve space in the Reserve Space box.
-
Specify the maximum space that can be used by the mount path by choosing either the Use until free space on mount path reaches Reserved Space or Do not consume more than n GB options.
-
-
Click OK.