HI Guys,

 

I can't seem to find out why write speeds to my unraid are so low. Scenario is as follows.

 

I was trying to send a large file (>1GB) to a share on my newly set up unraid -> Speed only goes up to ~ 26MB/s

Tried again with a SSD Pool share instead of array as target : Same result.

Connected my laptop with disabled wifi via cable to the same switch as unraid is connected to: Only slightly better rate but still <30MB/s

I changed the LAN cable for the unraid pc and the one between the switch to which unraid is hooked up and the main router/switch in my network.

 

Unraid Home screen shows: 

 

eth3:  1000 Mbps, full duplex, mtu 1500   --> should be capable of >100MB/s

Inbound:  226 Mbps

 

I tried to simplify as much as possible by writing straight to an NVME share und eliminating faulty LAN connections.

 

I am thinking this has to be some kind of driver issue.

 

These are my lan Ports in system devices. As far as I can tell, the controller name is correct.

 

IOMMU group 18:			 	[8086:125c] 03:00.0 Ethernet controller: Intel Corporation Ethernet Controller I226-V (rev 04)
IOMMU group 19:			 	[8086:125c] 04:00.0 Ethernet controller: Intel Corporation Ethernet Controller I226-V (rev 04)
IOMMU group 20:			 	[8086:125c] 05:00.0 Ethernet controller: Intel Corporation Ethernet Controller I226-V (rev 04)
IOMMU group 21:			 	[8086:125c] 06:00.0 Ethernet controller: Intel Corporation Ethernet Controller I226-V (rev 04)

 

Diagnostics are attached. What else can I try to find the problem? Any kind of help is greatly appreciated!

nas-diagnostics-20240203-1722.zip

Write speed internally array to cache nvme is fine (190 MB/s)

Try writing a file size larger than 5GB.  Depending on what the process is that is figuring your write speeds, the time may include a lot of time that is not actually the file transfer itself but may include things necessary to set things up for the transfer.   Unraid Share file allocation process is particularly slow as it adds another layer of software to the normal Linux file creation. 

 

I looked at your shares and it appears that you are caching writes to your shares.  Normally, using a SSD  (or NVME) cache drive for a share will take good size files speeds close to 1Gb/s speeds. 

 

Also try using the 'Write-reconstruct' option as shown below:

 

IF trying these does not work, post back with what you tried and what were the results.

 

One more thing, have you checked the speed transferring a large file back to your PC?

This is writing from pc to unraid: (looks the same from another pc)

copy from unraid to pc:(looks the same on other pc as well)

copy array share to nvme share internally

 

None of the shares involved use secondary storage.. To me it is obious that the target drive is generally fast enough and CAN write much quicker. Data intake or export over LAN seems to be the problem. I have not tested the reconstruct write setting since the target is a nvme drive, the setting seems to be for turnable drives and drive performance doesnt seemt to be the issue.

 

 

On 2/3/2024 at 6:17 PM, deebeo said:

problem. I have not tested the reconstruct write setting since the target is a nvme drive, the setting seems to be for turnable drives and drive performance doesnt seemt to be the issue.

The setting applied to drives in the main array regardless of what type of dtive they are.

 

sounds like you need to run iperf tests in both directions to check what speed you are getting over the network.

Using iperf3 across multiple different devices and jackpoints throughout my network I worked out that writing to unraid from devices within the same VLAN worked completely fine. When tried writing or reading from PCs in another VLAN is when things slowed down siginificantly. I am using a Unifi Dream Machine which seems to be overpowered by VLAN routing larger amounts of data passing through. I opened another Lan Port on unraid and connected it to my second VLAN which holds my devices of daily use. This completely fixed the issue.