Compress a PDS.

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Trupti Pawar
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Joined: Wed Feb 24, 2016 11:30 am

Compress a PDS.

Post by Trupti Pawar »

Scenario: I have a PDS which has a lot of members. That PDS is full and no more compress.
Question: I need to increase size of this PDS without delete define rename. Is there a way to increase the size dynamically?
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zum13
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Joined: Thu May 04, 2023 12:58 am

Re: Compress a PDS.

Post by zum13 »

Hello.

As far as I'm aware, there isn't really a way around it. If you've used the primary and all the secondary extents or all the entries in the directory then you need to change the allocation information and the only way around that is the reallocate/copy/delete/rename method.

One possible alternative that I have heard of (but haven't tried) is to migrate the dataset to HSM then recall it, the idea being that HSM will try to allocate the recalled dataset such that the primary extent will be large enough to hold the entire content of the dataset. What I don't know is whether this affects the size of the member directory; if that's your problem and it doesn't change, then migrate/recall won't help. Unfortunately, I don't have access to an HSM enabled system right now to be able to try it.

I've not really used PDS datasets for a while. I tend to allocate PDSE datasets instead as they are a little more flexible, don't need compression, and don't have a fixed size member directory.
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