Unraid question

[Ravendarat]

Ok so right now I just have a windows 11 PC running three 8tb drives in RAID 5. Im thinking of changing it up to UNRAID and adding in 3 16tb drives. My questions are

A) can I just move my current array into the new platform, transfer the data onto the new 16tb drives and then wipe the old 8 tb drives out and add them into the array?

B) if A is true than do I only need to sacrifice one 16 tb drive for redundancy of the new RAID or will I need more since I am adding the 8tb drives in as well?

C) how much RAM would be ideal to have on board

D) should I have some kind of NVME drive in this system as well or just the usb drive and the spinning disc?

E) The biggest folders I can move at times can end up being 400-500 gb, is there anything I can do to not have this take 24 hours or more to accomplish?

 

Thank you all for any help you can provide

I should point out that I plan on using my current 14600K set up I have with a LSI SAS card to handle the sata ports

[ChrisLoudon]

5 minutes ago, Ravendarat said:

Thank you all for any help you can provide

I should point out that I plan on using my current 14600K set up I have with a LSI SAS card to handle the sata ports

 

Hi buddy,

 

A) If you want to have a fault tolerant array in Unraid then you'll need to have some way of moving the data from the existing drives which I imagine will be NTFS, then onto the UNRAID array which will be something like XFS.

 

Ideally, you want to try and remove one of your existing 16TB drives from the Raid 5 array and get ALL of the data on that. You will then setup your UNRAID array with 1 x 16TB as parity, then another as the only storage disk. You then move all the data from the old 16TB drive onto the array. Once done, you can then get the 2nd 16TB drive into the array. 1 x 16TB for Parity then 2 more for storage.

 

B) The only real rule with UNRAID is the Parity drive needs to be the same size or larger than the largest drive in the storage pool so you are free to add more drives as long as its 16TB or smaller. I've got 7 drives in mine and they're all different sizes.

 

C) Yes. UNRAID benefits from having a faster SSD / NVMe for a cache drive. This doesn't need to be massive but its great to have all incoming files hit the faster drive first then it is moved to the slower array at a later date / time. Docker Containers and VMs also tend to run from the cache drive to speed things up.

 

D) I dunno.

 

On point (A) - I must admit I'm not 100% sure on that but hopefully someone else here can either confirm or deny what I've said but I'm pretty sure whenever I've added a new drive, its always warned me all data would be destroyed.

[ChrisLoudon]

I should also mention, unless you're planning on doing a hell of a lot more with the NAS than just storage, the 14600k is absolute overkill. Mine runs very nicely with PLEX, Pi-Hole and NZBGet on an old 3770K

[ChrisLoudon]

Sorry, I glossed over the existing 3 x 8TB drives. Either way, if you are thinking of getting any number of 16TB drives, you'll want to start the array with 1 x 16TB for Parity then work from there.

[porina]

1 hour ago, Ravendarat said:

Ok so right now I just have a windows 11 PC running three 8tb drives in RAID 5. Im thinking of changing it up to UNRAID and adding in 3 16tb drives. My questions are

A) can I just move my current array into the new platform, transfer the data onto the new 16tb drives and then wipe the old 8 tb drives out and add them into the array?

Probably not. Wont say it is impossible, but probably not worth the pain and risk to try if it was possible. How is the raid 5 set up? Hardware? Windows? Either way, getting it recognised correctly in Unraid isn't something I'd personally want to try.

 

It would be safer if you create the Unraid system, then move your files over to Unraid.

 

Out of interest, how much total data is there on the 3x8? Could it fit on one 16TB disk? I'm wondering if that might open other routes to moving data around. e.g. move all your data off the raid 5 onto one or two 16TB drives as necessary. Use the remaining 16TB disk as well as the now freed 8TB disks to setup Unraid. Somehow get the data off the 16TB drives with data onto the array, then wipe and add it to array also. Yes, this could take forever, and there is a risk if any disk fails. I'm guessing if you have data on 3 disks in raid 5 you're not that adverse to some risk!

 

Moving this much data around is going to take a lot of time however you do it, but it is a one time pain. You might have to do it overnight on several days.

 

1 hour ago, Ravendarat said:

B) if A is true than do I only need to sacrifice one 16 tb drive for redundancy of the new RAID or will I need more since I am adding the 8tb drives in as well?

The way Unraid works it is creates parity data to protect data drives. You can have as many data drives fail as you have working parity drives, and still recover data. Having one parity disk means you can fully recover from any one disk failing. Because the parity disk needs to hold recovery data for the used space, that is why it needs to be same or bigger than any data disk. Compared to most other array types, Unraid has the benefit that if too many disks fail so that you can't fully recover, data on surviving disks is still intact and accessible. So you could use 1x 16TB as parity, 2x 16TB as data, as well as 3x 8TB as data, and fully recover from any ONE data disk failing.

 

1 hour ago, Ravendarat said:

C) how much RAM would be ideal to have on board

If you're not running other server stuff, doesn't really matter. I've ran it on as little as 4GB before, for pure storage. If you have more, it does turn into a bit more disk cache.

 

1 hour ago, Ravendarat said:

D) should I have some kind of NVME drive in this system as well or just the usb drive and the spinning disc?

Strictly optional. Most common use would be as write cache, but if you care about redundancy, you'd need TWO so they can be mirrored. The default way Unraid works is very slow at writing, as it will read-modify-write the parity data depending on what data is written. This means you get about half the sequential speed of a disk. They do this because it means only the data disk being written to needs to be spun up, as well as the parity disk(s). Other disks can remain idle to save power. See next section for alternative option.

 

Note when writing, you're going to be limited by whatever connection method, usually the network speed. Roughly, 2.5GbE is generally sufficient to max out hard disks. 5 GbE would match SATA SSDs, and you'll need faster to make use of NVMe.

 

Note if you do end up using it as a server, the cache disks can be used to hold data for those services, and if they benefit from the perf, you can put them on there instead of the main array.

 

1 hour ago, Ravendarat said:

E) The biggest folders I can move at times can end up being 400-500 gb, is there anything I can do to not have this take 24 hours or more to accomplish?

You can turn on turbo writes. When you write, instead of the read-modify-write operation, it will read all other data disks apart from the one you're writing to, and since it knows the data being written, it can calculate the new parity data. Sequential write speed is that of single native disks. In the case of mismatched ones, the speed of the slowest disk.

 

1 hour ago, Ravendarat said:

I should point out that I plan on using my current 14600K set up I have with a LSI SAS card to handle the sata ports

Agree with Chris that CPU would be overkill for just file storage. But if you have it already, it'll be more than fine.

[Jarsky]

On 10/14/2025 at 7:35 AM, Ravendarat said:

A) can I just move my current array into the new platform, transfer the data onto the new 16tb drives and then wipe the old 8 tb drives out and add them into the array?

No; build the new array; setup your shares; then copy all the files over to your new array. Once all copied then you can move all the 8TB disks over, pre-clear them and add them to the array as data disks. 

On 10/14/2025 at 7:35 AM, Ravendarat said:

B) if A is true than do I only need to sacrifice one 16 tb drive for redundancy of the new RAID or will I need more since I am adding the 8tb drives in as well?

Theoretically you should have a parity disk for every 5 disks; I generally run 1 parity for every 8 disks. One is fine. 

On 10/14/2025 at 7:35 AM, Ravendarat said:

C) how much RAM would be ideal to have on board

UnRAID doesnt use RAM for anything (other than to run in memory), a couple of gigs is fine; but you might want to run Dockers or VM's which will require RAM. 

On 10/14/2025 at 7:35 AM, Ravendarat said:

D) should I have some kind of NVME drive in this system as well or just the usb drive and the spinning disc?

Depends on the speed you need. If its archival with low writes; then no need to add complexity. SSD caching in UnRAID acts like a virtual space; and has to *offload* to the array with a timed mover process. It's not a true CoW Cache that persistantly writes from the cache to the array. 

On 10/14/2025 at 7:35 AM, Ravendarat said:

E) The biggest folders I can move at times can end up being 400-500 gb, is there anything I can do to not have this take 24 hours or more to accomplish?

Are you saying you have another machine you move to/from? Moving around the same share is basically instant (depending on your disk rules). 

 

**The replies are based on using UnRAID's own feature; ZFS is another story which UnRAID also supports**