Dear all,
I’ve just bought a DAS to have a nice attached storage enclousure for my HDDs. But when I want to create a pool it complains about “duplicate serial numbers”. I’ve read about the problem in different forums, but is there a solution?
I wouldn’t like to have an ugly separate disk “power units” for the 3.5 inch disks just to be able to make it work.
Thak you for your help!!
KR
Rok
How is the “DAS” unit connected to your TrueNAS? USB is not supported for storage pools and there is no way around that that does not have a very high probability of eventual data loss.
USB 4… DAS also has Raid1 option which should actually mean that the software seeas it as one drive but it doesn’t… It’s a shame… because DAS is a great solution for “home users”… it’s certanly allot nicer than have 2 cheep disk bays connected to the mini pc…
2 cheap disk bays via USB are also not supported at all and will almost certainly lead to data loss.
What’s so difficult to understand about this? Do you want to lose precious data? No? Then don’t even consider USB. Get a case with internal disk bays and a main board with four or more SATA ports. Done.
Yeah seems to be more of a “I don’t want to use proper hardware” problem… Neither mini PCs nor USB enclosures are recommended for truenas…
Understood :-), thank you for your input.
A DAS (consisting of a JBOD, where multiple HDDs are aggregated in RAID1) connected to a (True)NAS via USB.
I don’t know if one could build something more unreliable and unpredictable than this…
It may sound a bit harsh when one is warned so strongly, but in this forum there seems to be almost every day, at least one case where someone is asking for help to prevent their data from being gone forever.
I think, with such an abstract setup, in the event of a failure, even here nobody could help…
It’s hard enough not to shoot yourself in the foot, even when you stick to the recommendations and best practices.
I picked up a Supermicro JBOD type expansion chassis for really cheap. There is no motherboard in it but otherwie it is a regular chassis. They have a real Supermicro backplane (either SAS2 or SAS3 depending on what you find), redundant power supplies and a passive card with external connectors (forget the connector designation but it is standard for the application) that the backpane connects to. Connect a cable between the chassis card connector and an actual HBA IT mode card with external connector in the server and now you have a real external expansion chassis that supports hot swap and SAS/SATA drives. These can also be daisy chained. Truenas immediately sees the chassis and the drives installed in the chassis without errors or complaint and all the drives are available for vdevs and assigning to the pool or for creating a second pool.
There are other issues with USB attached disks, than just duplicate serial numbers and reliability:
