Hey everyone,

I am using a DS920 with 3x12TB Seagate IronWolf Pro (ST12000NE0008) running SHR1. The drives are close to capacity, and I was thinking of adding a new drive of around 18TB or 20TB for now. Had a few questions and would greatly appreciate your input:

1) Is it okay to mix the Pro drives with Exos? Pro costs nearly double the price of Exos in the UK. I have heard Exos drives tend to be a bit louder, but the NAS is in a closet where the noise won't be so audible. Any other disadvantages in going Exos and not Pro?

2) Will the upgrade be as simple of as plugging in the drive, opening up the storage manager, and building the pool? Anything else I need to check beforehand?

3) Synology's RAID calculator did indicate that at least 6TB will be unused if using an 18TB drive. Plan to replace one of the 12 with the 18 in a few months, which seems to free up the unusable space. For this, do I just take out one of the 12TB drive, swap in the 18TB, and then rebuild the pool again?

The NAS is just being used for media storage to play with Plex for now.