Greyhole is a system module that uses Samba to create a storage pool of all your available hard drives (whatever their size, however they're connected).
In additionFrom this pool, it also allows you to create redundant copies of space is allocated for all Shares participating in the files you store, in order to prevent data loss when part of your hardware failspool.
From this poolIn addition, space is allocated for all Shares participating it also allows you to create redundant copies of the files you store in the poolshares. You can use this to prevent data loss when part of your hardware fails.
In short, Greyhole offers: