Upgrade to Ultra 4 Plus, Max storage capacity

Steve 46 wrote:
1. If I were to load up the Ultra 4 Plus with four 2TB HDD's and use the X-RAID configuration for redundant backup, what is going to be my maximum actual storage capacity? I'm assuming it is going to be 4TB but wanted to confirm.

For the default single drive failure protection you would get 6 TB of available storage, not 4. If you went with protection against two drive failures you would get 4 TB. It is best not to think about this as "backup" - you should still have an independent backup.

Steve 46 wrote:
2. I am going to backup all data and remove the two HDD's I have in the Ultra 2 Plus and install these drives into the Ultra 4 Plus to start. During the initial setup of the Ultra 4 Plus will it need to re-format the drives thereby erasing all data or is there a way to set up the X-RAID without erasing the data on the HDD's?

Since they are both in the same family, you should be able to simply more the drives over with no problem. You should make a backup first though.

However, there is a benefit to doing a factory default/drive wipe with all four HDDs installed. There is an 8 TB ceiling on expansion. So if you start with 2 TB available storage, you won't be able to expand beyond 10 TB. However, if you factory default with all the drives installed, you will start with 6 TB of available storage, allowing expanstion up to 14 TB.

Steve 46 wrote:
3. Regarding future expansion, when I am ready to add two more HDD's to the Ultra 4 Plus do they have to be the exact same model of Hitachi HDD's?

No.

Steve 46 wrote:
4. Finally can someone offer any thoughts on the "Link Aggregation" feature using the two ethernet ports. Does this improve performance in a home use environment? Any other thoughts or tips relating to upgrading to a higher capacity NAS are appreciated.

Link aggregation is only applicable on the Pro line, as it is a business feature. So you will not get it on an ultra plus. It won't improve performance for a single user, though there is an improvement if you have multiple devices accessing the NAS at the same time. It is nice to have, but in my view the main reasons for home users to consider the Pro is the generally faster CPUs and the longer warranty.