So Unraid is thinking that my new 4TB parity drive I've just put in isn't the biggest drive... The Toshiba which is also a 4TB drive is the biggest drive in the list there, everything else is 2TB or under. So why can't I use my new drive for parity?

I would suggest you post your system’s diagnostics zip file (obtained via Tools -> Diagnostics) attached to your next post do we can see exactly what is going on.

Diags will confirm, but if Unraid is complaining then it's not the biggest, might be related to the RAID controller in use.

Thanks for the reply, I didnt think about the diagnostics until you said it so here's the zip file

 

hpeproliant-diagnostics-20210429-1850.zip

 

Also quite new to having unraid and a server, the array card that's in it is a HP Smart Array P440AR, I got taught how to add drives to that but wasn't told if I even need to add the drives to it for them to work...

Edited April 29, 20215 yr by SmokeyOdin

 disk0: size: 3906985764

disk11: size: 3907018532

 

As you can see it's slightly smaller, almost certainly because of the RAID controller, it's not using all the space to create the volume, it reserves some of it.

 

 

2 minutes ago, JorgeB said:

 disk0: size: 3906985764

disk11: size: 3907018532

 

As you can see it's slightly smaller, almost certainly because of the RAID controller, it's not using all the space to create the volume, it reserves some of it.

 

 

 

Wonderful 😫 I'm guessing there isnt a way in the array software to minimise the amount it reserves?

6 minutes ago, SmokeyOdin said:

I'm guessing there isnt a way in the array software to minimise the amount it reserves?

It depends on the controller, but likely not, it's one of the reasons we don't recommend RAID controllers for Unraid.

3 minutes ago, JorgeB said:

one of the reasons we don't recommend RAID controllers for Unraid.

Another reason, your diagnostics show Unraid isn't getting SMART for any of those disks, so it can't tell you anything about their health.

You should be able to change the  HP Smart Array P440AR, to run i HBA mode and it will just pass the disks through without messing with them

5 minutes ago, m0t0k0 said:

You should be able to change the  HP Smart Array P440AR, to run i HBA mode and it will just pass the disks through without messing with them

 

Will that affect any of the data on the current drives?

9 hours ago, SmokeyOdin said:

Will that affect any of the data on the current drives?

You'll need to do a new config since the disks name will change and will very likely get an invalid partition layout on those disks, that can be fixed but requires rebuilding them one by one (and obviously you'd need to have a valid parity).