Hi everyone,

 

I am a new user to Unraid and so far I have been enjoying the convenience it provides. :D

I do run into an issue lately with cache drive and Array Drives having poor read/write speed to PC and Mac. 

 

Here are my specs:

Unraid Version: 6.8.1

Motherboard: Gigabyte B85M-D3H

CPU: Xeon 1275L V3

RAM: 16GB DDR3 1666

Drives: 

- Cache: 1TB Crucial MX500 (SATA3)

- Parity: 4TB WD Red 5200RPM (SATA3)

- Array: 2x 4TB WD Red 5200RPM (SATA3) &  2x 2TB WD Black 7200RPM (SATA2)

Network hardware: CAT5e ethernet cables both from PC to router and router to NAS. R6300v2 router. It should have Gigabit Ethernet speed. 

 

My motherboard have 2 SATA2 ports, I gave them to the 2TB WD Black, and up until now, no data has been written to the SATA2 drives. So we can rule out protocol bottleneck.

 

The file I tried to transfer is around 10GB (1080p movie file) Which should have pretty high transfer speed. 

When duplicating the same file in the same directory on the cache drive (Crucial MX500) I get this speed. Which is ok. I can live with 70~100mb/s speed.

This is also the speed I have when transferring from Download to Movie folder.

 

The problem happen when I tried to copy from Cache/Array Drive to Pc and from PC to Cache/Array Drive. The speed is notoriously slow.

 

Here are the suggestions I tried:

- Dynamic Trim Plugin (ran manually and automatically)

- Balance / Scrub the partition

- Run extended SMART test on cache, no error output

- Installed Turbo write even though it only affect Array drives (I dont see any speed increase on any of the drives sadly)

- Reboot, and transfer without starting any docker/vm, no effect

- Parity is not running

 

Here is the dd command I saw from one of the threads to check my cache transfer speed which looks good.

(I know root is bad practice but lets just ignore that for now :D)

 

Array Drive:

 

Some additional information:

- Cache disk and all WD Red are brand new.

- The folder I tried to copy from and copy to are both in cache=YES mode.

- Tunable is left default, since Unraid 6 should auto optimize it.

- Unmounting unassigned disks (portable hard drives) did nothing

- I dont think it is SMB configuration issue either because it worked for around a week without any problem.

 

Diagnostics and SMART for Cache SSD are in attachments.

 

Let me know if I miss any diagnostic info. Appreciate any help :D

 

tower-diagnostics-20200917-1416.zip tower-smart-20200917-1426.zip

From system/ethtool in those diagnostics:

	Speed: 100Mb/s

1G ethernet often degrades to 100M when 1 wire isn't working for some reason. Check ports, plugs, cables, switches, router.

Thanks for the fast reply.

 

I have replaced the ethernet cable and can verify that it indeed working at full speed again.

 

Thank you.