Administration Guide › SFS Overview › Allocation of Space in User Storage Groups › Interaction Between an SFS Manager’s Allocation Limit and a User Storage Group’s Allocation Limit

Interaction Between an SFS Manager’s Allocation Limit and a User Storage Group’s Allocation Limit

The combination of allocation limits on user storage groups and allocation limits on managers allows for the most efficient distribution and use of space on your system. These limits allow for the incomplete use that user IDs make of the space they can use in a user storage group.

CA VM:Director does not know how many blocks of space exist in a user storage group, or how many are available at any time, until it tries to process an SFS manager’s request to allocate space to a user ID. At that time, it considers two factors:

• Does this allocation raise the SFS manager’s allocation from the specified user storage group beyond the SFS manager’s allocation limit?
• Does this allocation raise the user storage group’s allocation beyond its allocation limit?

Example:1

The following tables show the size and limits for User Storage Group 3 and the amount of space Manager A, Manager B, and Manager C can allocate from User Storage Group 3:

If the physical size of user storage group 3 remains 1,000 blocks and its allocation limit remains 300 percent, at least one of these managers will not be able to allocate his full amount of allocable space. This is because the managers’ effective allocable space exceeds the user storage group’s effective allocable space.

Example:2

The SFS configuration known to CA VM:Director includes the following:

SFS manager BGEDDES enrolls user ID SREED in user storage group 2, allocating him 3,000 blocks of space, with this command:

vmdirect enroll sreed 3000 2 vmxa

CA VM:Director finds the following in processing this command request:

It then calculates the proposed values and determines the request can be filled: