Total number of extents is limited to ?253? over multiple volumes. On Mon, Apr 7, 2025 at 2:48 PM Jousma, David < [email protected]> wrote:
> I think the point of my question wasn’t worded clearly. The problem is > poor allocation coding over the years where coded primary and secondary > allocations are NO WHERE NEAR what is really needed. But because we have > 100’s of volumes in the pool, and a dataclass that allows 59 volume > multi-volume dataset, the problem is masked because the dataset can get 123 > extents on each of the 59 volumes. With a 20-1 reduction in volumes in > the pool(1TB EAV’s replacing 20 mod-54’s), there might not be 59 volumes in > the pool, and that dataset will now take an x-37 abend that we will take > the heat for. > > That is what I am trying to avoid. Seems like my only option is to reduce > the size of the EAV so that there are more volumes, or make the developers > fix their JCL allocations. I was hoping for the pixie dust to work > around the latter, but I don’t think there is anything. It would be nice > if (here is the pixie dust), that on dataset extent processing, if some > number of x space is requested, but is below some threshold percentage of > the current file size, or less than some site customizable minimal > trk/cylinder quantity that it would get overridden to something larger. > > Dave Jousma > Vice President | Director, Technology Engineering > > > > > > > > > -----Original Message----- > > > From: IBM Mainframe Discussion List [email protected] On Behalf > > > Of Jousma, David > > > > > > Sent: Friday, April 4, 2025 9:21 AM > > > To: [email protected] > > > Subject: Migrating Storage pools to EAV > > > > > > 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. > > > > > > So, we are finally biting the bullet and making 1TB EAV volumes our > standard for UCB relief, etc. One "habit" my Storage team over the years > had done to mask poor dataset allocations was to make the mainly used > DATACLAS multi-volume, with a max of 59 volumes. It was before my time, but > I'm 99% sure that was done to avoid x37 abends for max extents. Now that we > are going to EAV's, we'll be clearing off the mod-54's and DISNEW them. And > with a 20-1 reduction in physical volumes, there will likely be pools that > had say 100 volumes, that could end up with just 5 EAV's. > > > > > > I'm not a storage guy by craft, so am wondering if there is any magic > dust to help with this other than making the owners of the poorly allocated > files make adjustments to their allocations? > > > > > > Dave Jousma > > > Vice President | Director, Technology Engineering > > > > > > > > This e-mail transmission contains information that is confidential and may > be privileged. It is intended only for the addressee(s) named above. If > you receive this e-mail in error, please do not read, copy or disseminate > it in any manner. If you are not the intended recipient, any disclosure, > copying, distribution or use of the contents of this information is > prohibited. Please reply to the message immediately by informing the sender > that the message was misdirected. After replying, please erase it from your > computer system. Your assistance in correcting this error is appreciated. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > -- 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 [email protected] with the message: INFO IBM-MAIN
