Well, there are many guidelines regarding sizing of VTOC and its index.
Obviously it depends on your data.
Not on size of data.
Not on number of datasets (but closely)
It depends on number of extents.
In simple words the more small datasets, the more VTOC. The more avg
extents per dataset the more VTOC.
Of course YMMV, for SPOOL volumes one may expect one dataset, one
extent. In this case index is unnecessary.
From the other hand few tracks lost is not big deal nowadays and common
rules are convenient.
Last, but not least - although you EAV volume can be 100GB or 1000GB
big, there won't be track-sized extents, since the smallest one in 21
cylinders. That means a lot of data, big datasets, relatively small
number of extents.
My advice: keep a table of VTOC&index sizes, preferrably in form of
ICKDSF statements.
One for 3390-1,
One for 3390-3
One for 3390-9
One for 3390-27
One for 3390-54
One for "small" EAV (let's say <250GB)
One for "large" EAV (>250GB, up to current limit of ~1TB).
It's easier to have a table than to reinvent the wheel.
How to get it? One of the sources can be ICKDSF job from ServerPac.
Obviously it is off-topic (3390A), but still about the mainframe,
fortunately. ;-)
--
Radoslaw Skorupka
Lodz, Poland
W dniu 22.05.2025 o 21:33, rpinion865 pisze:
I found this by doing search,
ICKDSF manual Appendix C. VTOC/Index are 983 / 50, 2944 / 150, 9828 / 491,
and 19656 / 980 for mod 3, 9, 27, 54 respectively.
"Confidentially doc, I am the wabbit."
Bugs Bunny
Sent with Proton Mail secure email.
On Thursday, May 22nd, 2025 at 3:25 PM, Mike
Schwab<000005962a42dc49-dmarc-requ...@listserv.ua.edu> wrote:
It allocates the expanded area in 21 cylinder chunks. So you need to
expand a Mod 54 VTOC / Index by 4/315ths.
On Thu, May 22, 2025 at 12:48 PM Steve Beaver <
0000050e0c375a14-dmarc-requ...@listserv.ua.edu> wrote:
They are just huge meaning 5 Mod54's
-----Original Message-----
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On
Behalf Of Pommier, Rex
Sent: Thursday, May 22, 2025 7:59 AM
To:IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: [EXTERNAL] Re: 3390A’s
Not a dumb question. In the context of PAVs and all that fun stuff,
3390Bs are the "real" volumes and the 3390As are the PAV volumes.
Rex
-----Original Message-----
From: IBM Mainframe Discussion listibm-m...@listserv.ua.edu On Behalf
Of Jay Maynard
Sent: Thursday, May 22, 2025 6:43 AM
To:IBM-MAIN@LISTSERV.UA.EDU
Subject: [EXTERNAL] Re: 3390A’s
All right, dumb question time. What's a 3390A/3390B? From context, it's
not the size of the volume, is it?
On Thu, May 22, 2025 at 2:45 AM Radoslaw Skorupka <
00000471ebeac275-dmarc-requ...@listserv.ua.edu> wrote:
W dniu 22.05.2025 o 01:42, Steve Beaver pisze:
Is anyone using 3390A’s?
IMHO everyone, maybe except zPDT users.
All current disks system do support PAV And there are many features
(not necessarily paid) related to PAV - WLMpav, HyperPAV, SuperPAV.
And some others like MIDAW or HPF.
IMHO usually you get a package containing all the features.
What's your problem with 3390A?
--
Radoslaw Skorupka
Lodz, Poland
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
