Teraspace Characteristics

Teraspace is a large temporary space that is local to a job. A teraspace provides a contiguous address space but may consist of many individually allocated areas, with unallocated areas in between. Teraspace exists no longer than the time between job start and job end.

A teraspace is not a space object. This means that it is not a system object, and that you cannot refer to it by using a system pointer. However, teraspace is addressable with space pointers within the same job.

The following table shows how teraspace compares to single-level storage.

Table 1. Comparing teraspace to single-level storage

Attributes	Teraspace	Single-level storage
Locality	Process local: normally accessible only to the owning job.	Global: accessible to any job that has a pointer to it.
Size	Approximately 100 TB total	Many 16 MB units.
Supports memory mapping?	Yes	No
Addressed by 8-byte pointers?	Yes	No
Supports sharing between jobs?	Must be done using shared memory APIs (for example, shmat or mmap).	Can be done by passing pointers to other jobs or using shared memory APIs.