Hello
I don't know how big is your storage, but you have configured something like 100 disks of 4TB (= 4000gb)
You define capacity of your pool configuring (Maximum Volume Bytes x Maximum Volumes)
Is interesting to set smaller volumes because if you have some volume error you will loose less data.
If you consider one hard disk of 1TB with a Full Backup daily of 100GB and you want 30 days retention, you will not reach it, because 30 x 100GB = 3.000gb or 3TB, so you only will reach 10 days retention (10 * 100GB) = 1TB