I can confirm that changing the "immutabilityPeriod" in the store's xml file works and also it seems to be the only possible way. As said you could request an enhancement for this to get it implemented in DPDUtils and/or the GUI.

I also want to stress that this period is set store-wide. So for any object in the store, already existing or new ones, the period will be modified to the new value that is set.

Hi Andy,

I was confused for a moment as I didn't see that message. But that's because I usually use the omnimm CLI command to erase expired media. When running it from the GUI, I was able to reproduce that popup message and most likely you see it because of this global parameter:

# DeleteUnprotectedMediaMinimumAge=seconds

# default: 86400
# Determines what is the minimum age of the medium to be deleted
# by omnimm -delete_unprotected_media.
# If a medium age is lower than this value (from time of
# creation), then it is skipped by omnimm.

While it's a good idea to keep some delay here, it doesn't need to be a full day. Maybe you can set it to 3600 seconds or something like that. For testing purposes, I typically set it to 10 seconds in my test environment.

I also wrote a document about this some time ago:

Support Tip: Why is my B2D medium not deleted while it is unprotected?

And yet another one which you may find interesting:

Support Tip: Why are immutable media purged from the Internal DataBase?

Hi Andy,

I was confused for a moment as I didn't see that message. But that's because I usually use the omnimm CLI command to erase expired media. When running it from the GUI, I was able to reproduce that popup message and most likely you see it because of this global parameter:

# DeleteUnprotectedMediaMinimumAge=seconds

# default: 86400
# Determines what is the minimum age of the medium to be deleted
# by omnimm -delete_unprotected_media.
# If a medium age is lower than this value (from time of
# creation), then it is skipped by omnimm.

While it's a good idea to keep some delay here, it doesn't need to be a full day. Maybe you can set it to 3600 seconds or something like that. For testing purposes, I typically set it to 10 seconds in my test environment.

I also wrote a document about this some time ago:

Support Tip: Why is my B2D medium not deleted while it is unprotected?

And yet another one which you may find interesting:

Support Tip: Why are immutable media purged from the Internal DataBase?

Hi Koen,

Yes, that's it, those are the parameters which were stopping me deleting the media. To confirm after a day the media did get auto-deleted by the daily delete of unprotected media. I realise now I was trying to do something that in reality I would not normally do, run a backup and then delete it immediately. I would normally set of oneoff test backup to retention of 1 day in DP and it would auto-delete the next day. Immutability would stop it if I'd set the immutability to more than 1 day.

So I've set the immutability to 1 day, left the MinimumAge option as 1 day, which is good enough for me. I've hit another issue, but I'll write that up in a new thread as it's unrelated. 

Cheers, Andy