Given the complexity of today's data processing environments, it is almost impossible to provide methods to predict the exact storage requirements of a software product.
The following tables provides rough estimates about the fixed storage requirements of Entire Net-Work and its various components, ignoring operating system-related storage requirements, which typically vary from installation to installation.
Table 1 contains the amounts of storage obtained from the operating system based on parameter specification or appropriate defaults. It does not include storage areas that are directly related to the operating system, such as operating system control blocks, I/O-related buffers, and control blocks (except where they are part of Entire Net-Work program modules or data areas).
Table 2 contains the amounts of storage obtained from the Entire Net-Work buffer pools by the control module and the various line drivers.
Table 3 contains special storage requirements of the line drivers (such as special common system storage areas) in the various operating system environments.
|Entire Net-Work buffer pools*||Asynchronous buffers||AS(X)||Part||Virt.M||AS(X)|
|Entire Net-Work trace table||AS(X)||Part||Virt.M||AS(X)|
|Entire Net-Work control blocks||general||AS||Part||Virt.M||AS|
|ADAIOR data areas||general||AS||Part||Virt.M||AS|
|(for trace table, ECB list, etc.)||about 2KB||about 2KB||about 2KB||about 2KB|
|AS||from address space (private, below 16MB if XA or XS)|
|AS(X)||from address space (private, above 16MB if XA or XS)|
|SYS||from system GETVIS area (VSE in VAE mode)|
|Part||from partition (VSE not in VAE mode)|
|Virt.M||from virtual machine|
|Comm.Pool||from common memory pool|
|Statistic||Buffer Pool Types|
|Segment size||64||64||512||2KB or 4KB|
|Control module buffer pool usage||UB||MSG
|Queue manager buffer pool usage||BLK||BLK|
|IUCV line driver buffer pool usage||2WAY
|DCAM line driver buffer pool usage||WTO||SMBLK|
|BLK||Storage for outgoing transmission blocks (after compression and blocking), from short-term pool or page-fixed pool, depending on line driver requirements. Storage requirements for one transmission block include, in addition to the messages contained, 48 bytes for a transmission block header.|
|INTQEL||1 segment for each IUCV message received (held until reply).|
|MSG||All messages sent or received; output messages kept until acknowledged by the access method, input messages kept until processed.|
| The size of a message can be computed in the following way:
56 bytes for a message header
+ maxpath * 2 bytes for a node stack
+ 128 bytes for UB, ACB, etc.
+ size of FB, RB, SB, VB, IB to send or receive
|PATHS||4 * the number of possible IUCV paths specified in the MAXCONN option of the CP directory (rounded up to nearest segment) + 1 segment per active IUCV path.|
|RECV||Storage for incoming message data until transferred to short-term buffers (in paging systems only).|
|RPLY||A reply buffer for each user request for a target on this node if the information returned by the target will not fit into the original message buffer (that is, if a large record buffer or ISN buffer is to be returned to the user).|
|SMBLK||1 segment for each message that cannot be sent in one transmission, kept until the message is acknowledged by the adjacent node.|
|UB||(only if 31-bit mode:) 64 bytes per user request for a target on this node, for the duration of the Adabas call.|
|WTO||Operator messages; kept until the message is written. DCAM: 2 asynchronous segments for messages from asynchronous routines.|
|2WAY||Storage for reply messages in the length of messages sent when the SEND 2WAY protocol is used (page-fixed in paging systems only).|
|Driver||Special Storage Requirements|
(for FLIH, SVC, subsystem vector table, IUCV buffers, interrupt queue elements, working storage, and the cross-product interface tables):
| z/OS: from CSA (SP228) or SQA (SP245)
VSE: from system GETVIS (page-fixed)
|DCAM||MAXBLK (for receive buffer):|
|BS2000/OSD: from AS|
NUMUSERS*256 is initially allocated from buffer pool storage for the Active Client Table (ACT). This value may dynamically expand if required.
In addition to the storage estimates shown in the table, approximately 250KB storage is required for executable code.