A +------------------------------------------------------------------+ | README file for BS2000/OSD-BC V6.0B | | | | Issue: July 2005 | +------------------------------------------------------------------+ The changes/extensions update the following manuals: [1] BS2000/OSD-BC V6.0 Introduction to DVS Issue December 2004 Order number: U4237-J-Z125-8 [2] BS2000/OSD-BC V6.0 System maintenance Issue December 2004 Order number: U2417-J-Z125-15 A Table of contents ================= Changes to the README file (history)..................... 1 1 NK-ISAM pools in data spaces............................. 2 2 Configuration of data spaces for NK-ISAM pools.............3 3 Default settings no longer evaluated for NK-ISAM...........5 4 Determining measurement values for NK-ISAM pools...........6 5 Expansion of the parameter set for NK-ISAM (ISAM)..........7 A - Page 1 - In the manual Introduction to DVS, chapter 21.9 NK-ISAM pools in data spaces (page 446 onwards) is to be added (chapter 1 up to and including chapter 4). In the manual System maintenance, a description of the new parameter MAXDSBN is also to be added (chapter 5) on page 104 of chapter 3.7 Default settings for NK-ISAM (ISAM). A - Page 2 - 1 New functions ================= From BS2000/OSD-BC V6.0B onwards, multi-task NK-ISAM pools are implemented as sections in data spaces with SCOPE=GLOBAL; this is true both for NK-ISAM pools explicitly defined by the user and for those configured as standard by the system. As a rule, this new implementation allows any NK-ISAM file to be buffered in a separate NK-ISAM pool; however, should the user wish to buffer several NK-ISAM files in a single NK- ISAM pool, this can also be accommodated. Below is some information concerning the migration of NK-ISAM pools in common memory pools to NK-ISAM pools in data spaces. Task-local NK-ISAM pools in which NK-ISAM files opened in SHARUPD=NO mode are administered continue to be implemented in the program space (privileged class 5 storage). With regard to implementation and usage, neither task-local NK-ISAM pools explicitly defined by the user nor those configured as standard by the system are subject to change since the previous version. A - Page 3 - 2 Configuration of data spaces for NK-ISAM pools ================================================== * Compatibility From BS2000/OSD-BC V6.0B onwards, NK-ISAM files that were previously (i.e. up to and including BS2000/OSD-BC V6.0A) buffered in multi-task NK-ISAM pools explicitly defined by the user are formatted in NK-ISAM pools of the same size, which are implemented as sections in a data space with SCOPE=GLOBAL. It is thus ensured that the previous performance behavior for these NK-ISAM files is maintained. * Restriction of the number of data spaces In order to avoid malfunctioning by saturation of the paging area, the number of data spaces available for multi-task NK-ISAM pools is restricted. The maximum number of these data spaces can be set using the startup parameter service (ISAM parameter set, new parameter MAXDSBN, see point 3). Default value: MAXDSBN=2. * Migration The preset values for the maximum number of data spaces for multi-task NK-ISAM pools (MAXDSBN=2) and for the size of such NK-ISAM pools (GLBPS=512) allow approx. 4000 NK-ISAM files, opened simultaneously in the SHARUPD=YES mode, to be buffered separately in separate NK-ISAM pools. If this limit is reached or exceeded, NK-ISAM files additionally opened in the SHARUPD=YES mode are assigned to already existing NK-ISAM pools in data spaces. In order to check or ensure that (almost) every NK-ISAM file opened in the SHARUPD=YES mode can be assigned to an NK-ISAM pool in a data space, the following steps are followed: - Determine the number of NK-ISAM files opened in the SHARUPD=YES mode (#FILES); this value can be issued before the switch to BS2000/OSD-BC V6.0B; - The storage area needed for buffering is then the corresponding multiple of the pool size preset by the startup parameter service. For the number of data spaces required (rounded up to the next largest multiple of 2GB): MAXDSBN = (#FILES * GLBPS) / 1000000 + 1 Note: The pool size is given in units of 2KB, so the size of a data space must be expressed in this unit: 2 GB = 1000000 * 2K. - The paging area may also need to be increased; the requirement for the data spaces for multi-task NK-ISAM pools is to be determined as (MAXDSBN + 1) * 2GB. A - Page 4 - * Determining the size of a multi-task NK-ISAM pool For an NK-ISAM file to be opened in the SHARUPD=YES mode, the size of a multi-task NK-ISAM pool (in units of 2KB) in which the relevant NK-ISAM file is to be administered can be determined by entering ADD-FILE-LINK in the command line. However, the system rounds this value up to the next largest MB limit. Example: /ADD-FILE-LINK LINK-NAME=,- SUPPORT=*DISK(ISAM-ATTRIBUTES=- *PARAMETERS(POOL-SIZE=1024)) A - Page 5 - 3 Default settings no longer evaluated for NK-ISAM ==================================================== Default settings for NK-ISAM pools can be configured using the startup parameter service (see manual System maintenance). Due to the modified default mechanism for NK-ISAM pools, the following parameters in the ISAM section are no longer evaluated in BS2000-OSD/BC V6.0B onwards: GLBDFPS Indicates the size for multi-task standard NK-ISAM pools in units of 2 KB DFPPROC Determines the mode for the assignment of multi-task standard NK-ISAM pools (provides for one or several standard NK-ISAM pools from the outset) GLBDFPN Determines the number of multi-task standard NK-ISAM pools provided for from the outset A - Page 6 - 4 Determining measurement values for NK-ISAM pools ==================================================== Contrary to earlier versions, multi-task NK-ISAM pools in data spaces are identified by the NK-ISAM file path name. For this reason, measurement values for multi-task NK-ISAM pools in data spaces must be recorded by entering the NK-ISAM file path name. More details on this may be found in the README file for SM2 version 15.0B ($TSOS.SYSRME.SM2.150.D or SYSRME.SM2.150.E). A - Page 7 - 5 Expansion of the parameter set for NK-ISAM (ISAM) ===================================================== From BS2000-OSD/BC V6.0B onwards the maximum number of data spaces to be provided for multi-task NK-ISAM pools can be defined by entering the newly introduced parameter MAXDSBN in the section ISAM: Possible values: 1 <= MAXDSBN <= 127 Default value: MAXDSBN = 2