Resize allocated space

Hello,

I have Flex appliance 5250 with 9.09 TB of storage capacity, it´s meaning, allocated 8.91 TB (97.97%) , Available 0.18 TB (2.03%) total 9.09 TB.

Disk Pools, Used capacity 1.77 TB , Available Space 4.91 TB of 6.68 TB of capacity.

I would like to create a new instance and apply immutability, but my issues, I have no free space in my storage.

I´ve been thinking , is it possible resize my allocated space. It´s meaning , I will reduce the allocated 8.91 TB to 4.5 TB.

I will get this one:

I have Flex appliance 5250 with 9.09 TB of storage capacity, it´s meaning, allocated 4.5 TB (47.97%) , Available 4.68 TB (52.03%) total 9.09 TB.

Then, next step creates new instance.

Does It make sense? And I can´t lose my backup save into the appliance.

I got two links

https://vox.veritas.com/t5/NetBackup-Appliance/Resizing-the-Storage-unit/td-p/521518

https://www.veritas.com/support/en_US/doc/130821112-151833038-0/v136269043-151833038

Thanks your help