I have a really odd problem on a new server I am building.

A Mini PC with two 5 bay USB disk enclosures which I am slowly adding disk to.

When I reboot the server, it randomly drops disks from the array, if I power everything off, wait a few minutes and restart, sometimes it takes one or two cycles before the disks become visible again and I can place them back into their correct array allocation.

 

I have also seen where one disks ID totally changed to a random name, yet again a reboot and the disk was "found" again with the correct ID.

 

Not sure how to solve this, any help ?

We don't recommend using USB for array or pool devices, it can cause a lot of different issues, including the ones you are describing.

I dont have the space for a real PC and external disks, so I only have this option.

 

Its odd, because sometimes, not even the USB boot drive is working, something is odd.

I have a new mini PC on order, hopefully it may help.

It can be a problem with the USB ports in that PC if the flash drive is also dropping, hopefully the new one works better, like I mentioned USB is generally not recommended, but there are some users using without major issues.

This must be an issue with the order that the USB disks are found at the hardware level.

 

I find that if I reboot, normally once, but sometimes twice, everything just works perfectly, all the disks are found in the right order etc.

 

its a shame this cannot be fixed somehow as using USB enclosures for low throughput needs are a cheap solution with Unraid.

2 hours ago, MartynK said:

This must be an issue with the order that the USB disks are found at the hardware level.

 

I find that if I reboot, normally once, but sometimes twice, everything just works perfectly, all the disks are found in the right order etc.

 

its a shame this cannot be fixed somehow as using USB enclosures for low throughput needs are a cheap solution with Unraid.

 

This is not an issue if the USB enclosure passes the drive serial numbers through to Unraid as that is the way that Unraid identifies drives, not by the order in which they initialise.

Odd because I have seen a number of occasions where there correct number of disks have been passed over, just they have just not dropped in to the correct allocation.

3 hours ago, MartynK said:

Odd because I have seen a number of occasions where there correct number of disks have been passed over, just they have just not dropped in to the correct allocation.

How are they connected?   If via USB then it is possible the serial numbers are not being passed through correctly.   Some USB enclosures pass them through while others do not.

Yes, the are USB and the serial numbers are being passed, it looks like some times they dont come through correctly, so the reboot clears things up and the are passed OK.

In longtime ago, I also use USB enclosure for the build, I buy two different 5 bays enclosure, the first one never reliable and the 2nd one finally reliable by adding a USB hub ( dedicate chips ) and change the firmware of the enclosure. Both enclosure architecture are USB to SATA phy + port multipler but they use different chips solution. Nowadays, some USB enclosure use different architecture, they are USB to USB hub + multiple USB-SATA phys, this may be more reliable, but still many issue could cause problem.

 

In simple say, you could try adding USB 3.X hub in between and test any different.