5tb

5TB drives should work fine. However if you use disks that are not on the compatibility list and encounter issues you may it be able to get support.

You would not hit the 16TB limit using RAID with 4x5TB disks in a 4-bay NAS unless you use RAID-0. Your volume capacity would be less than 16TB after allowing for redundancy and overheads.

However there is another limit to be aware of. You cannot expand a volume by more than 8TB over the life of the volume. So if your volume capacity was say 4.8TB when you last factory reset the unit you cannot expand past 12.8TB without backing up your data and doing a factory default with the disks in place.

However there is another limit to be aware of. You cannot expand a volume by more than 8TB over the life of the volume. So if your volume capacity was say 4.8TB when you last factory reset the unit you cannot expand past 12.8TB without backing up your data and doing a factory default with the disks in place.

i currently have 4x3tb and i'm planning to upgrade to 4x5tb. So my 10tb RAID NAS will still be under 12TB so if i understand correctly i should be fine ?

thanks!

It depends on what the capacity was when you last did a factory default. If you last did a factory default with 2x3TB disks in place you wouldn't be able to expand past roughly 10.8TB. What disks were in the NAS when you last did a factory default?

hmmmm i think i may had 2x2tb or 2tb+3tb when i last did a factory default :/

Then you had a 2 TB volume size (~1.81 TiB), and could expand to 9.81 TiB (10.78 TB). That's about 1.75 TB over where you are now - so adding another 3 TB drive will require a reset.

(edit - adding another 3 TB drive wasn't the question, which was going to 4x5TB)

sorry i meant i had 4x2tb or 2x2tb+3tb at last reset

the volume size was either 4tb or 5tb

4 or 6 (in power of 10 units). 4tb is the worst scenario, which is about ~3.63 TiB. The ceiling then becomes 11.63 TiB, which is 12.88 TB (power of 10). If you started with 6 tb, I think you end up at ~14.8 tb.

4x5TB gives you a 15 TB volume size, so either way I think you'd need a reset.

4x5TB gives you a 15 TB volume size, so either way I think you'd need a reset.

I don't understand... If i have 4x5tb it is 20tb total so if i need half of it for backups (raid) then i would have 10tb of data and 10tb of backup... Why do you say 15tb volume ?

Only 25% is needed for RAID-5 redundancy in that case. Basic rule of thumb for xraid single redundancy is to total all the drives, then subtract the largest. 4X5TB - 5 TB = 15 TB.

Similarly if you are running 4x3TB today, you have a 9 TB volume, not 6.

It is not a backup (keeping a full duplicate of the data). It is doing something more sophisticated.

Don't confuse RAID with backup. RAID (except RAID-0) provides redundancy/high availability. RAID-5 for example spreads your data and parity across your disks so that if any one disk fails data remains intact.

If you store important data primarily on the NAS you should backup that data e.g. to another NAS or some place else.

Have a read of Preventing Catastrophic Data Loss

Edit: beaten