The Init and Tuning Guide has a formula for DASD sizing , reading a bit...they want you to define the checkpoint for a secondary JES subsystem and start it up and 'see' if its the right size. :( but there is a formula in the guide
Specifying the storage of checkpoints on DASD When you have calculated the number of 4K records for the checkpoint, use Table 53 to determine the number of tracks or cylinders on DASD, and round up to the nearest whole number. Table 53. Number of 4K records per track and cylinder for various DASD devices DASD Device Type 3380 3390 9340 # of 4K Records per Track 10 12 10 # of 4K Records per Cylinder 150 180 150 Note: 1. Track 1 contains only the Check, Lock, and Master records, plus as many change log records (4K each) that will fit on the remainder of the track. Track 1 correction is needed because track 1 is typically not filled to capacity. 2. The change log records can overflow onto subsequent tracks. 3. If the data set is not large enough, JES2 issues the $HASP296 message to indicate the number of additional tracks required. (There is no penalty for over-estimating the number.) For example, 4K records require the following amount of space on DASD Device Type 3380 or 3390, if the number of 4K records for type 3380 is 376 and the number of 4K records for type 3390 is 378: DASD Device Type 3380: 38 tracks (376 / 10 = 37.6), or 3 cylinders (376 / 150 = 2.5) DASD Device Type 3390: 32 tracks (378 / 12 = 31.5), or 3 cylinders (378 / 180 = 2.1). ----- Original Message ----- From: "Lizette Koehler" <[email protected]> To: [email protected] Sent: Tuesday, January 17, 2017 10:02:57 AM Subject: How to calculate the JES2 Checkpoint and Spool Space Cross posting to TSO REXX and IBMMAIN Long ago IBM Created an APAR OY44087 which provided some guidance and formula on how to calculate space for the JES2 Ckpt and Spool space. I am looking to create a REXX/ISPF function or Excel to mimic this process. However it is lacking on how some of the newer control blocks, like BERTS, would affect this calculation. Does anyone have any idea how to create a process for generating the sizing for JES2 based on the newer resources that have been added since OY44087? I know if I try to increase a resource and there is insufficient space, JES2 will prevent the change from occurring and then tell me what it needs. I think issuing the command to "see if it works" is not a really practical method. Particularly if you really did not want to change it at that time. I looking to build a "what-if" tool that could help one validate the JES2 environment will be able to handle any resource changes. And if it cannot, then what should it be raised to. Thanks Lizette Koehler statistics: A precise and logical method for stating a half-truth inaccurately ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
