z13 created dataset LISTC & DCB,
STATISTICS
USER-DATA-SIZE----------------------------27761896449
COMP-USER-DATA-SIZE------------------------2689053885
SIZES-VALID--------(YES)
Management class . . : MC1GEND Allocated cylinders : 3,170
Storage class . . . : STANDARD Allocated extents . : 1
Volume serial . . . : TL0018
Device type . . . . : 3390
Data class . . . . . : COMP
Organization . . . : PS Current Utilization
Record format . . . : VB Used cylinders . . : 3,170
Record length . . . : 23552 Used extents . . . : 1
Block size . . . . : 23556
1st extent cylinders: 3170
Secondary cylinders : 250 Dates
Data set name type : EXTENDED Creation date . . . : 2021/07/01
Referenced date . . : 2021/07/22
Expiration date . . : ***None***
SMS Compressible . : YES
Extended Attributes NO
z15 created dataset LISTC & DCB
STATISTICS
USER-DATA-SIZE----------------------------27761896449
COMP-USER-DATA-SIZE------------------------3629379499
SIZES-VALID--------(YES)
Management class . . : MC1GEND Allocated cylinders : 4,279
Storage class . . . : STANDARD Allocated extents . : 11
Volume serial . . . : PL0024 +
Device type . . . . : 3390
Data class . . . . . : COMP
Organization . . . : PS Current Utilization
Record format . . . : VB Used cylinders . . : 4,279
Record length . . . : 23552 Used extents . . . : 11
Block size . . . . : 23556
1st extent cylinders: 150
Secondary cylinders : 99 Dates
Data set name type : EXTENDED Creation date . . . : 2021/07/22
Referenced date . . : 2021/07/22
Expiration date . . : ***None***
SMS Compressible . : YES
Extended Attributes NO
-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On Behalf Of
Chuck Kreiter
Sent: Thursday, July 22, 2021 4:34 PM
To: [email protected]
Subject: Re: zEDC compression on z13 and z15
[External Email. Exercise caution when clicking links or opening attachments.]
We went from z14 to z15's and didn't notice any difference in compression.
I would be curious to see listcat of both showing the user data size and the
comp data size as well as the dataset DCB attributes.
-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf
Of PINION, RICHARD W.
Sent: Thursday, July 22, 2021 3:55 PM
To: [email protected]
Subject: zEDC compression on z13 and z15
We migrated from a z13 to a z15 this past weekend. We are running z/OS 2.2,
z/OS 2.2 on the z13, and the same z/OS 2.2 on the z15. z15 maintenance was
applied to z/OS 2.2, and activated a couple of months ago. We are using the
same SMS configuration on the z15 as the z13, and that includes the zEDC
compression Data Class.
I restored a dataset that was created on the z13 using zEDC compression, and
needed to make a copy of the dataset on the z15. I was surprised to see an
almost 20,000 track difference between the z13 created dataset, and the z15
created dataset. I used the same SMS Data Class to make the z15 version of the
dataset.
Enter "/" to select action Tracks %Used
------------------------------------------------------------------------
Z13.CREATED.DATA.SET 47550 99
Z15.CREATED.DATA.SET 64555 100
SMS allocation messages for the z15 created dataset follows.
IGD17070I DATA SET Z15.CREATED.DATA.SET
ALLOCATED SUCCESSFULLY WITH 1 STRIPE(S).
IGD17160I DATA SET Z15.CREATED.DATA.SET
IS ELIGIBLE FOR COMPRESSION
IGD101I SMS ALLOCATED TO DDNAME (SYSUT2 )
DSN (Z15.CREATED.DATA.SET)
STORCLAS (STANDARD) MGMTCLAS (DE180DAY) DATACLAS (COMP)
VOL SER NOS= TL0018
I have not looked into the TCB/SRB I/O numbers of the
z13 creating job to compare against the z15 job.
Anyone have an idea as to why such a dramatic difference?
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