Storage below 16 MB report

The Storage below 16 MB report provides information on the use of MVS™ and CICS® virtual storage. It contains the information you need to understand your current use of virtual storage below 16 MB and helps you to verify the size values used for the CDSA, UDSA, SDSA, and RDSA and the value set for the DSA limit.

Table 1. Fields in the Storage below 16 MB report
Field Heading Description
Region size established from REGION= parameter The region size established from the REGION= parameter in the JCL. If the region requested was greater than 16 megabytes, the region established resides above 16 megabytes, and this field will be a minimum value of 32 megabytes.
Storage BELOW 16MB Description
Private Area Region size below 16MB The private area size below 16 MB, expressed in KB.
Max LSQA/SWA storage allocated below 16MB (SYS) The maximum amount of virtual storage allocated from the local system queue area (LSQA) and the scheduler work area (SWA) subpools below 16 MB, expressed in KB.
Max User storage allocated below 16MB (VIRT) The maximum amount of virtual storage allocated from the user subpools below 16 MB, expressed in KB.
System Use An amount of virtual storage available for system use.
RTM An amount of virtual storage available for use by the MVS recovery and termination manager included for calculation purposes, which could be allocated during a CICS region recovery and termination.
Private Area Storage available below 16MB The amount of storage below 16 MB that could be allocated by increasing the DSALIM parameter or by MVS storage GETMAIN requests.
MVS PVT Size The maximum MVS private area (PVT) size below 16 MB, expressed in KB.
MVS CSA Size / Allocated The MVS common system area (CSA) size and the amount of the MVS CSA allocated below 16 MB, expressed in KB.
MVS SQA Size / Allocated The MVS system queue area (SQA) size and the amount of the MVS SQA allocated below 16 MB, expressed in KB.
Current DSA Limit The current DSA Limit, expressed in KB.

Source field: (SMSDSALIMIT / 1024)

Current Allocation for DSAs The current amount of storage allocated to the DSAs below 16 MB, expressed in KB. This value may be smaller or larger than the current DSA limit.

Source field: (SMSDSATOTAL / 1024)

VIRT minus Current DSA Limit The total amount of user storage allocated/used below 16 MB minus the current DSA limit. This indicates the amount of user storage that is allocated below 16 MB, and is not allocated to the DSA.

Source field: ((VIRT - SMSDSALIMIT) / 1024)

Peak Allocation for DSAs The peak amount of storage allocated to the DSAs below 16 MB, expressed in KB. This value may be smaller or larger than the current DSA limit.

Source field: (SMSHWMDSATOTAL / 1024)

Current DSA Size The current size of the CDSA, UDSA, SDSA, or RDSA, expressed in KB.

Source field: (SMSDSASZ / 1024)

Current DSA Used The current amount of storage used in this DSA, expressed in KB.

Source field: ((SMSDSASZ - SMSFSTG) / 1024)

Current DSA Used as % of DSA The current amount of storage used in this DSA, expressed as a percentage of the current DSA size.

Source field: (((SMSDSASZ - SMSFSTG) / SMSDSASZ) * 100)

Peak DSA Used The peak amount of storage used in this DSA, expressed in KB.

Source field: (SMSHWMPS / 1024)

Peak DSA Size The peak size of the CDSA, UDSA, SDSA, or the RDSA, expressed in KB.

Source field: (SMSHWMDSASZ / 1024)

Cushion Size The size of the cushion, expressed in KB. The cushion forms part of the CDSA, UDSA, SDSA, or the RDSA, and is the amount of storage below which CICS goes short on storage (SOS).

Source field: (SMSCSIZE / 1024)

Free Storage (inc. Cushion) The current amount of free storage in this DSA, expressed in KB.

Source field: (SMSFSTG / 1024)

Peak Free Storage The peak amount of free storage in this DSA, expressed in KB.

Source field: (SMSHWMFSTG / 1024)

Lowest Free Storage The lowest amount of free storage in this DSA, expressed in KB.

Source field: (SMSLWMFSTG / 1024)

Largest Free Area The length of the largest contiguous free area in the CDSA, UDSA, SDSA, or RDSA, expressed in bytes.

Source field: (SMSLFA / 1024)

Largest Free Area as % of DSA The largest contiguous free area in the CDSA, UDSA, SDSA, or RDSA, expressed as a percentage of the current DSA size.

Source field: ((SMSLFA / SMSDSASZ) * 100)

Largest Free/Free Storage An indication of the storage fragmentation in this DSA. This value is calculated by dividing the Largest Free Area (SMSLFA) by the Free storage (SMSFSTG). If the ratio is small, this DSA is fragmented.

Source field: (SMSLFA / SMSFSTG)

Current number of extents The number of extents currently allocated to this DSA.

Source field: SMSEXTS

Number of extents added The number of extents added to the DSA since the last time statistics were recorded.

Source field: SMSEXTSA

Number of extents released The number of extents that were released from the DSA since the last time statistics were recorded.

Source field: SMSEXTSR

Getmain Requests The number of GETMAIN requests from the CDSA, UDSA, SDSA, or RDSA.

Source field: SMSGMREQ

Freemain Requests The number of FREEMAIN requests from the CDSA, UDSA, SDSA, or RDSA.

Source field: SMSFMREQ

Current number of Subpools The current number of subpools (domain and task) in the CDSA, UDSA, SDSA, or RDSA.

Source field: SMSCSUBP

Add Subpool Requests The number of ADD_SUBPOOL requests to create a subpool (domain or task) from the CDSA, UDSA, SDSA, or RDSA.

Source field: SMSASR

Delete Subpool Requests The number of DELETE_SUBPOOL requests (domain or task) from the CDSA, UDSA, SDSA, or RDSA.

Source field: SMSDSR

Times no storage returned The number of times a GETMAIN request with SUSPEND(NO) returned the condition INSUFFICIENT_STORAGE.

Source field: SMSCRISS

Times request suspended The number of times a GETMAIN request with SUSPEND(YES) was suspended because of insufficient storage to satisfy the request at that moment..

Source field: SMSUCSS

Current requests suspended The number of GETMAIN requests that are currently suspended for storage.

Source field: SMSCSS

Peak requests suspended The peak number of GETMAIN requests that were suspended for storage.

Source field: SMSHWMSS

Requests purged while waiting The number of requests that were purged while suspended for storage.

Source field: SMSPWWS

Times cushion released The number of times a GETMAIN request caused the storage cushion to be released. The cushion is said to be released when the number of free pages drops below the number of pages in the cushion and there are no more free extents available to increase the size of this DSA.

Source field: SMSCREL

Times Short-On-Storage The number of times CICS went SOS in this DSA, where SOS means that the cushion is currently in use, or at least one task is suspended for storage, or both. This field applies to the CDSA, UDSA, SDSA, and RDSA.

Source field: SMSSOS

Total time Short-On-Storage The accumulated time that CICS has been SOS in this DSA.

Source field: SMSTSOS

Average Short-On-Storage time The average time that CICS has been SOS in this DSA.

Source field: (SMSTSOS / SMSSOS)

Storage Violations The number of storage violations recorded in the DSA. This field applies to the CDSA, UDSA, SDSA, and RDSA.

Source field: SMSSV

Access The type of access of the DSA. Values are CICS, USER, or READONLY. If storage protection is not active, storage areas revert to an access type of CICS, except those in the RDSA.
  • CICS - access is CICS key
  • USER - access is user key
  • READONLY - access is read-only protection

Source field: SMSACCESS