Removing a drive

[tmarsh12345]

Been using my Lockerstor 4 AS6604T for a while now, recently bought a 16TB HDD and couldn't figure out how to replace a failing drive so just copied of the data, made a new volume and re-installed. All OK until I realised that I'd changed from JBOD to raid 6 and my drives are 16 8, 4 and 2TB so I've just under 6TB useable. I'm intendinmg to have 4 16TB's when I have the funds but meantime, if I remove the 2TB will that double the useable space?

If so, can I remove the 2TB drive and still retain the data?

[Nazar78]

Raid 6 requires 4 minimum disks and allowed to have two disks failures but the two disks space are unusable. In your case RAID 6 is only 4TB of usable space not 6TB or do you meant RAID 5? Removing any one (raid5) or two (raid6) of the disks will not increase any space in fact the array will be in a degraded state. Putting back the disk(s) the array will trigger a resync.

So I'm not sure what you're trying to achieve by removing the 2TB because unless you manually run commands to force degrade the array, which is officially unsupported, you'll not be able to use that particular bay slot for other purposes.

[tmarsh12345]

Raid 6 requires 4 minimum disks and allowed to have two disks failures but the two disks space are unusable. In your case RAID 6 is only 4TB of usable space not 6TB or do you meant RAID 5?

Thanks. I have raid 6, useable disk space is 5.4TB.

So I'm not sure what you're trying to achieve by removing the 2TB because unless you manually run commands to force degrade the array, which is officially unsupported, you'll not be able to use that particular bay slot for other purposes.

I had read that raid 5 and 6 uses the smallest size disk size in calculating storage capacity. My setup's smallest disk is 2 TB and I thought if I made the smallest 4 that would double my storage but I see from your answer that I need 4 disks. Is that the 4 way it works? If I had 2 4TB disks along with the 16 and 8? As I said, this is tempoprary until I get the larger diosks, just using what I had lying around.

[Nazar78]

You cannot just remove one disk, you'll need to start fresh in RAID 5 of 4+8+16TB disks to get 8TB worth of space.

Your RAID 6 space seems not right, post some screenshots, you can verify here https://www.seagate.com/sg/en/products/ ... alculator/.

[tmarsh12345]

Your RAID 6 space seems not right, post some screenshots, you can verify here https://www.seagate.com/sg/en/products/ ... alculator/.

Sorry, my mistake, Windows included a 2TB external USB drive I had plugged in. Thanks for all your help, looks like I'll have to speculate!!

[HighYieldCd1]

What you’re running into is expected behavior with RAID 6 when drives of very different sizes are mixed. RAID 6 limits usable capacity based on the smallest drive, and then reserves the equivalent of two drives for parity. In your case, with 16TB, 8TB, 4TB, and 2TB disks, the system effectively treats all drives as 2TB, which is why you’re seeing just under 6TB of usable space.

Removing the 2TB drive will not double your usable capacity while keeping your data safe. If you pull that disk, the array will go into a degraded state, and you won’t automatically regain space. RAID does not dynamically rebalance capacity upward without a full rebuild.

If you need more space right now, the safest approach is to back up your data, delete the RAID 6 volume, and recreate a new array using only the larger disks (or temporarily switch to JBOD). Otherwise, the best option is to wait until you can replace all drives with matching 16TB units and then rebuild the array properly.

Just like planning storage upgrades, financial planning also benefits from clear calculations—tools like https://highyieldcdcalculator.com

help avoid surprises by showing realistic outcomes in advance.