Slow SMB Read Speed, Fast Write | ZFS on Linux | Ubuntu 18.10

[Legotan]

Hello Guys,

I got some strange problems with a new ZFS-Setup and SMB-Share:

when copying files from a client machine to the server, I see around 400 - 500 MB/s transfer speeds. If I copy the same file from the server to the client, I only reach 150 MB/s. That seems way too low...

On the client machine I use a ramdisk for testing. Client and Server are connect via Connect-X2 10Gbit cards.

On the server side I got a Dell R710 with dual-socket quad cores and 144GB RAM. The server runs on Ubuntu 18.10 and has 10 4tb hdd's in raidz2.


Any hints or suggestions how to increase the Server to Client transfer speed?

If you need any configurations files or infos, just ask

Thank you very much!

Alex

 

[Monoman]

Please use fio for file transfer tests. It will present better results for us to help you. I believe it's client, but fio will say .

 

[Legotan]

Thank you for your response.

I now ran fio on the client machine, but still have the same problem: The reads are way slower than the writes..

 

[RTM]

Sorry I don't have a magic quickfix.
Have you tried narrowing down the possible issues by reducing components involved?

Why not start by removing the network, and benchmark the local disk array's performance?
If that works, you could try mounting the share locally on the server (I have never done this, but I assume it will work), and do the same again.
If that works, limit the amount of network equipment between server and client to ideally just a single cable.

Other random ideas: look into whether server and client use the same MTU

 

[acquacow]

I had similar issues that came down to windows group policies getting set/unset in a windows update.

See the fix info here:
https://forums.freenas.org/index.ph...-reads-iperf-is-fine.69795/page-2#post-483471

-- Dave