About RAID1 Mirroring...
Your ACS10 is factory equipped with dual-HDDs configured for RAID 1 (Mirroring). The storage capacity available for music content is one-half of the total HDD drive capacity. For example, the ACS10-16TB model makes available 8TB for music library storage and the remaining 8TB is a mirrored copy.
If you wish to use the total storage of both drives, you must use the ACSManager App to delete the RAID configuration.The RAID deletion process will take only 1-2 minuets and you will see both Music1 and Music2 folders upon completion. Please note that any existing content will be deleted during this process.
If you wish to restore the RAID 1 configuration later, you can do so by command in the ACSManager App. However, be aware that any stored content will be deleted and it will take approximately 14 hours to create the RAID 1 configuration. We urge you to keep a safe copy of your library stored externally to the ACS10 when reconfiguring so you can import that content back into the ACS10 post RAID 1 restoration.