[Solved] Slow transfer speeds

[Mokkisjeva]

Hello,

 

I have an issue when transferring files from my PC to my Unraid server. Under the parity check it says "Duration: 17 hours, 47 minutes, 48 seconds. Average speed: 124.9 MB/sec" So I'm assuming the transfer speed would be ~120MB/sec at best. 

 

So I made a dummy file in windows at 100GB, the first 6-8GB the transfer speed is ~110MB/sec, then it falls to ~50MB/sec.

 

Funny enough, the reason I wanted to make this post is because when I transfer actual files it usually runs at ~50MB/sec and drops to ~1MB/sec for about 20sec then speeds up to ~50MB/sec. And so it fluctuate back and forth. So how do I troubleshoot and figure out why the slow transfer speed? It doesn't matter if I move from wifi laptop or cabled PC or even from the VM running on the server. (This got fixed after doing a unraid update)

 

Edit:

I just sent a 25GB file from the Unraid server to my PC and it transferred 110MB/sec - 117MB/sec.

Then sent it back to Unraid, and same story as before. After about 8GB it slows down to half the speed (50-60 MB/sec)

 

Edit 2:

Forgot to add Cache drive, but same story. After nearly 8GB transfer at full speed it drops to half for the rest of the duration.

 

Edit 3: 

Changed use Cache from YES to PREFER. Fixed it, stable 110+ MB/sec transfer speed.

Edited March 30, 2019 by Mokkisjeva

[Squid]

10 hours ago, Mokkisjeva said:

Edit 3: 

Changed use Cache from YES to PREFER. Fixed it, stable 110+ MB/sec transfer speed.

You do realize though that that setting means that the file(s) will stay on the cache drive and never get moved to the array.  Setting it to "YES" means that new file(s) get written to the cache drive and then moved to the array.  If you were constantly overwriting the same file during your tests, then it was never hitting the cache drive if the file already existed on the array.

[Mokkisjeva]

Oh shit, no wonder using the mover filled the cache rather than empty it!

 

Then I still struggle with 50% transfer speed, how do I fix this?

[Mokkisjeva]

Any ideas anyone?

 

Transfer to unraid = 120mb/s for almost 8gb then drops to 30-50mb/s for the rest of the duration.

Transfer from unraid = 120mb/s constantly.

[JorgeB]

1 minute ago, Mokkisjeva said:

Any ideas anyone?

This is expected using default write mode, see turbo write.

[Mokkisjeva]

7 minutes ago, johnnie.black said:

This is expected using default write mode, see turbo write.

 

Thank you so damn much Johnnie!!!!!

 

Made a 50gb dummy file to transfer, had a flawless write speed without dipping ones!