Issues with USB external drives

[mangusbrother]

I had a Unifi XG Server lying around and I have just installed TrueNas Core on it.
I have 2 internal SSD's in the server (+1 for OS) that I am using as a main pool for my NAS needs.
I however have 3 USB HDD's lying around that I was planning to use as a rolling offline backup . All these drives work fine when tested individually on another pc. They are stripe, and I understand the risk of data loss here but since i was going to have several backups across several drives, and the drives have no other use really I would like to go forth with this.

I am however encountering several issues along the way.

1. If i wire in 3 drives, only 2 of them seem to appear in the Disks view on the UI. I have tried two combinations here. In both cases I somehow can only get 2 of my external disks to appear (Disk screen shows up to 5)
1a. A mix of drives connected to both my Usb 3.0 back ports, and my Usb 2.0 front ports.
1b. A usb hub connected to my Usb 2.0 front panel with alll 3 drives on it.
2. Even with just 2 disks visible, Whenever i try to create a pool (force) on any of my 2 drives, the UI seems to get stuck on "Create Pool - Starting job..."

What can I do to get these integrated properly please?

 

[mangusbrother]

Update on this situation

I left the Starting job screen there for an hour and it seems to have created it. There was an error "Pool with this name already exists" but now the pool is actually shown

I did it again for the second drive and it worked in seconds now

I still cannot get the third drive to appear however.

 

[Arwen]

Part of the issue can be non-unique IDs for the drives. Some vendors use the ID of the USB to disk adapter chip, instead of the serial number of the underlying hard or solid state drive. See this Resource. It is not completely relevant to your backup use case, but some details do apply.

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

I too use USB attached external storage for backups. But, I use exactly 1 drive at a time;

How to: Backup to local disks

How to: Backups to local disks Overview: This subject comes up often enough that I thought I would start a post of how I do it. Specifically I back up my TrueNAS to a hot-inserted, locally attached disk, then when done, hot-remove and take...

www.truenas.com

 

[mangusbrother]

Hmm I fear that might indeed be the case. The enclosures I am using are identical which adds to this probability.

The USB drives I was going to set as one being daily and the other weekly, to minimise risk of both failing simultaneously if there is some form of issue, and basically cause I had extra drives lying around that could serve this purpose.

Thankfully the two that are currently connected, seem to be working fine. Will monitor it a bit more to make sure no major issues i guess