New install of BUE 21.4 onto a new server, brought over the old disk-to-disk SAN and tape array. After using the BUE Migration Assistant program I've noticed that in the Backup Options for a job, under Storage it lists "Any disk storage (2 devices are in this pool)" under Storage pools. I only have the single disk-to-disk SAN configured as storage, where is this second disk storage coming from? When looking at All Storage, I don't see additional disk-based storage options. Was lead to this "discovery" when double-checking settings after the migration due to disk-to-disk jobs taking twice to three times as long to backup prior to migrating to a new server.
You can set the jobs to that disk storage and check how it goes.
The setting may have carried over from older BE.
In this case, the performance could be due to something else as well.
If OS is 2016, set exclusions for BE in MS Defender
Additionally if you manually create a new storage pool [Configure Storage - Storage pools - Storage device pool - give it a name etc] then this will create a new entry in the storage tab showing you All Storage Pools, which will allow you to drill down into tthe details of any one of the pools there, eg the 'Any disk storage' pool as well as the one you just created manually.
In this way you'll be able to see exactly what is included in the 'any disk storage' pool.