USB drives - yes or no

[malaki86]

I attempted to set up an Unraid server using my current setup, which consists of 3 Lenovo ThinkCenter M600 pcs (8gb ram, I5-N3700 cpu). These are thin clients, ultra-compact with no expansion capabilities. My drives are in a 5-bay USB3 enclosure, and it works fine under OpenMediaVault. In fact, it was fin in Unraid until I added a m.2 SATA cache drive & plugged in a separate 8Tb usb drive for parity. The 3 machines each run specific services to spread out the entire server load. 

 

I'm buying a new-to-me Dell Optiplex 7050 MT with an i7-7700 and 40-48Gb of RAM. The plan is to eventually move the motherboard to a standard case (yes, it will fit), along with an IT-mode LSI SAS controller, but for right now, I have to use the same USB3 enclosure. 

 

The question is if Unraid should be more stable in the much more powerful machine, while still using the USB drives. I can install a SATA drive internal for parity, along with an NVME cache drive (single). With the original setup (m600 thin pc), I would lose access to the shares after 5-10 minutes, forcing a restart of the server and all of the machines using those shares.

 

No, USB isn't perfect, but I'm on a budget and have to baby-step my upgrades. If it's not recommended, I can stick with OMV until it's been transplanted and has the drives directly connected.

[malaki86]

No one?

[Frank1940]

USB is a pig-in-a-poke as far as the hardware goes.  Some hardware is far superior in quality in terms of both design and manufacture.  So there is not an easy answer as to whether your particular hardware will function satisfactorily in the Unraid environment. 

Edited February 9, 2023 by Frank1940

[Hoopster]

On 2/6/2023 at 4:34 AM, malaki86 said:

No, USB isn't perfect, but I'm on a budget and have to baby-step my upgrades.

In general USB attached drives are not recommended for permanent array storage with Unraid.  For "attached when needed" unassigned devices there are usually no issues.

 

The problem is that USB implementations vary by motherboard/chipset and some are not very stable.  They are often prone to random disconnects.  If USB-attached drives are in an array, they cause havoc, especially with parity, if they disconnect in the middle of a write operation.  Heavy traffic such as large file transfers or transferring a large amount of small files can trigger a USB drive to disconnect.

 

Your mileage may vary and perhaps your hardware is stable enough with USB that it may work for you with Unraid.  There is just no sure way to tell before you try it.

Edited February 9, 2023 by Hoopster

[malaki86]

Ok, that's sort of what I figured. On my initial trial, it seemed to run great until I added the parity drive, but I also added a cache drive at the same time.

 

I'll just stay with OMV until I can get all of my drives attached via SAS/SATA.

[malaki86]

On 2/9/2023 at 5:43 PM, Hoopster said:

In general USB attached drives are not recommended for permanent array storage with Unraid.  For "attached when needed" unassigned devices there are usually no issues.

 

The problem is that USB implementations vary by motherboard/chipset and some are not very stable.  They are often prone to random disconnects.  If USB-attached drives are in an array, they cause havoc, especially with parity, if they disconnect in the middle of a write operation.  Heavy traffic such as large file transfers or transferring a large amount of small files can trigger a USB drive to disconnect.

 

Your mileage may vary and perhaps your hardware is stable enough with USB that it may work for you with Unraid.  There is just no sure way to tell before you try it.

When I first tried, the array drives were rock solid. It wasn't until I added a parity drive, also on USB, that the problems surfaced.

 

Now I'm thinking about trying it again, but with the parity drive on one of the on-board SATA ports.

[trurl]

If you insist on running USB on the array, better to do so without parity. That way if a drive disconnects, it won't have to be rebuilt because it is out-of-sync, since without parity there is nothing to be in sync with. Better if pools are only single disk for a similar reason.