See https://www.ibm.com/docs/en/zvse/6.2?topic=SSB27H_6.2.0/fe6rf_optimizing_casize_disksizes.htm
A 3390 MOD-1 has 1,113 cylinders. Each 3390 cylinder has 15 tracks. Each 3390 track has 56,664 bytes. 1,113 x 15 x 56,664 = 946,005,480 There are 946,005,480 bytes in a 3390 MOD-1 disk drive. Or roughly 0.946 GB. The PC-compatible disk drives in your DS8k frame have a fixed block architecture (FBA) which, after being RAIDed together (RAID is 'Redundant Array of Independent Disks'), create virtual FBA volumes consisting of multiple 1GB (1,000,000,000) extents. These extents are 'raw' storage. However, z/OS only recognizes count key data (CKD) formatted tracks and native 3390 drives (with a multiple platters on a single spindle) have not been manufactured in this century. To remedy this, when the DS8k frame is installed, each 1 GB FBA extent is configured as 1,113 CKD cylinders. Larger virtual 3390s are then constructed from these configured extents. Not exactly sure what you're looking at in the DS8k GUI, but '1.99Kmod1' sounds like '1.99 k mod1' 3390s, or 1.99 x 1000 x 946,005,480 bytes. Or 1,882,550,905,200 bytes. Or 1.88 TB Notice that almost 5.4% of the raw storage has been 'lost' when the FBA disk is configured as CKD storage. Now add the space 'lost' to VTOCs, VTOC indices, VVDSs, and unused space, both within the boundaries of an allocated data set and the free space on each 3390 volume. The remainder is data. Not sure how the all-flash DS8900F works as far as configuring and 'lost' space. -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Mike Schwab Sent: Thursday, January 19, 2023 3:59 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: KMOD1 DS8k box CAUTION: This email originated from outside of the Texas Comptroller's email system. DO NOT click links or open attachments unless you expect them from the sender and know the content is safe. 846,236,160 bytes * 1990 M1s is 1,684,009,958,400 bytes. On Thu, Jan 19, 2023 at 3:53 AM Mike Schwab <mike.a.sch...@gmail.com> wrote: 3390-1 is 846,236,160 bytes. Divide by 1000 or 1024 three times for a Gigabyte factor, or four times for a Terabyte conversion factor. On Thu, Jan 19, 2023 at 1:29 AM Jake Anderson <justmainfra...@gmail.com> wrote: Hello I was going through the storage usage in DS8K Gui login And I can see the utilization of CKD Pool is given as 1.99Kmod1 Is there a way to convert these value in Terabyte? Jake -- Mike A Schwab, Springfield IL USA Where do Forest Rangers go to get away from it all? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
