Seemingly insanely slow write speeds

[InReasonNotFish]

I've just moved to 6.12.4 of unRaid and was looking at how cache vs array is now handled for shares.  I clearly didn't understand and set one of my media shares to be primary-cache.  Overnight the mover kicked in and filled my cache drive.  

I tried to fix this by changing the share to primary-array but the mover seems to be taking forever so I killed it and I'm using MC to move things back from the cache (I'm moving from /mnt/cache/media to /mnt/disk#/media.

Here's the problem... I'm getting transfer speeds of about 10MB/s and it seems like I should be getting about 150MB/s.  I know that my parity drive has to be written as I write back to the array but I didn't think it would have this kind of impact.  I've got about 900Gb to move off of the cache and this could take forever.

My array is WD Red drives so I know they aren't build for speed but again, I should be getting about 10x the speed I'm seeing.

Any suggestions?

 

rs-diagnostics-20231027-1152.zip

[itimpi]

Do you have Turbo Write enabled?

[InReasonNotFish]

3 hours ago, itimpi said:

Do you have Turbo Write enabled?

Yes.

[JorgeB]

Most of your drives, including parity, are SMR, so degraded write perforce is expected.

[InReasonNotFish]

10 hours ago, JorgeB said:

Most of your drives, including parity, are SMR, so degraded write perforce is expected.

But this level of degradation?  10Mb/s or lower can't be explained by SMR, can it?

Oh, and I do have plans to move my 1 6TB CMR drive into the parity slot.  But that has to wait until the rest of my rebuild is complete.

Edited October 28, 2023 by InReasonNotFish

[JorgeB]

16 hours ago, InReasonNotFish said:

But this level of degradation?  10Mb/s or lower can't be explained by SMR, can it?

It can, I have an SMR only array and it's common to get <5MB/s for 3 to 5 minutes every few minutes during large transfers.