Mixing disks of different sizes in a vdev is not allowed

[zazray]

hi
I want to build vdevs and I have 2 wd 2tb sata connection and 1 tb external use USB 3 port and use raid z but it shows an error Mixing disks of different sizes in a vdev is not allowed but all the same size how I fix

 

[sretalla]

I'm pretty sure that the USB disk is really a slightly different size (eveb 1 byte different will produce the message you're seeing (which you can probably override with the Force option ... not shown in your screenshot, but would be below and to the left).

But, you shouldn't do that (if you care about the data you will put in that pool).

Why you should avoid USB attached drives for data pool disks

This subject has been coming up quite often in the last year or 2. Perhaps because of TrueNAS SCALE has brought forth some attention to TrueNAS in general and ZFS in specific. Please note that this is about USB attached storage for ZFS data...

www.truenas.com