Dear Unraid friends

 

I have a little issue...or let's say I don't know if it's a issue but somehow I'm not happy with that:S

 

I got a new and my first unraid Server.

 

Intel NUC with I7 10th Gen and a FANTEC Case with 3 x 6TB Seagate Ironwolf disks. The Fantec Case is attached with USB 3.

 

So I installed 6.9.0-rc2 (because of the drivers) and made some shares:

 

Share Media--> Started to copy from my synology over my Windows machine. Alright with a NVMe drive as cache it's reaching 100MB/s without issues. And now my issue: When the Cache disk writes to the array...it's slooooow 18MB/s ....is this normal?

 

When I download a movie from my Media share which is already on the array disks...I reach about 80MB/s but not always. With my Synology I reached always the full bandwith:S

 

I know that unraid is not using a classic raid so the movie is just on 1 Disk...so 80MB/s is okay in that case but still not the MAX.performance from the disk.

 

Did I forget something or did I something wrong?

 

Config:

3 disks and one of them is parity.

1 NVMe drive as cache

LAN: PC and Unraid in same network and same subnet

 

I will also attach the diagnostics. I would be very happy if somebody could check it and tell if I did something wrong:) Many thanks in advance

 

tower5-diagnostics-20201226-1839.zip

Edited March 26, 20215 yr by Magarac
Solved

USB is not a good choice for connecting disks in the array or pools. This is especially true if you are going to have a parity disk. Ideally, parity operations happen in parallel, and all writes to the array update parity at the same time. And parity update requires also reading at least parity and the disk to be updated, or reading all disks if you are using "Turbo Write". When each disk has a separate connection all disks can be accessed simultaneously.

 

Also, USB connections can be unreliable, and if it disconnects, the array will be out-of-sync and require rebuilding.

 

And, there are other problems that can arise when using USB connections and USB enclosures for array or pool disks.

 

If you really must use USB for your disks then I recommend you give up on the idea of having parity.

Many thanks for your fast response.

 

Oh that's bad:( I would like to keep the parity otherwise it would be a huge loss of data in case of a disk failure:S

 

So you would also not reccomend eSATA or thunderbolt connection I guess?.....if so it looks like I need to rebuild my setup

Whatever you do parity is not a substitute for backups. Plenty of more common ways to lose data besides disk failure.

 

SAS enclosures can give multiple connections with a single cable but require SAS controller in the computer.

Alright, thank you for your answer and help. I will try to reorganize my setup and see what happens:)