Write speed to OMV dropping after 1 sec to 10 MB/s

Chris G. · 14. Januar 2016

Hi there!
I just installed OMV to my small NAS (see signature).
I am mostly using it as a NAS for my Home-Network. My PC and my Laptop both use the SMB shared files.
Read speeds were definetly great! (95+ MB/s, which you can see in the picture). However in the course of trying to get better write speeds I installed some updates from the Manager and my read speeds (pc reads from server) went down to 60 MB/s.

However the write speeds... Those are not great at all!

It starts of at around 50 MB/s, but only for one to two seconds, then it drops to around 10 MB/s and stays there until it is finished.
I tested this with an .ISO of 636 MB.
Tests with a folder of 145 MB were similar, the speed starts to build up, to a maximum of 40 MB/s and then it drops to around 10 MB/s quite fast.
The problem exists with my PC, my Laptop and also between the two drives in my NAS (copy file from 3TB drive to 4TB drive via Windows explorer).

The Advanced Power Management is set to: 254 Maximum performance, maximum power usage
The Automatic Acoustic Management is set to: Max performance and max acoustic output

The CPU usage is only scratching the 60% mark.
The 15 minute load average stays under 0,8.
The drive temperatures sit at a nice cool 35°.

Samba Version 3.6.6

Entries in SMB extra config:

Code

max protocol = SMB2
max xmit = 65535
socket options = TCP_NODELAY IPTOS_LOWDELAY SO_SNDBUF=65535 SO_RCVBUF=65535
read raw = yes
write raw = yes
max connections = 65535
max open files = 65535

I really hope that you can somehow help me!
Thanks in advance!
Chris

Chris G. · 15. Januar 2016

I just changed my smb.conf to get back to my good read speeds of 100 MB/s:
Entries in smb.conf:

Code

read raw = yes
write raw = yes
socket options = TCP_NODELAY SO_SNDBUF=65536 SO_RCVBUF=65536
max protocol = SMB1
max xmit = 65535

The write speeds were not affected by that at all.

ryecoaaron · 15. Januar 2016

What Windows are you running? Did you ever try:

Code

socket options = TCP_NODELAY IPTOS_LOWDELAY SO_RCVBUF=65536 SO_SNDBUF=65536 SO_KEEPALIVE
strict sync = no
sync always = no
use sendfile = yes

Chris G. · 15. Januar 2016

Windows 10 Pro (and Windows Home on my Laptop)

These settings only degrade my read performance.
The "write-problem" that it starts of well and then goes to 10 MB/s still exists

ryecoaaron · 15. Januar 2016

You could try backports samba 4.1 and set max protocol to smb3 but it is difficult to go back if it doesn't work.

Chris G. · 15. Januar 2016

Well then this is not really an option...
I will try it in a VM.

ryecoaaron · 15. Januar 2016

Good idea. That is what I always recommend. I know Win10 would be happier with smb3.

Chris G. · 16. Januar 2016

Well, I tried to run OMV in a VM, but there I ran in different problems (such as not being able to access the vm-share at all). So that I did not try any further.
I set up the FTP-Service and transferred a huge file via FileZilla to my Odroid and there is the same problem.
I conclude that the slow write speeds have nothing to do with Samba but with something different with my system (maybe move the thread? But where?)

Today I encoutered another problem.
My main PC does not recognize the odroid in the network and there is no way I can access my shares although I can access them with my Laptop...
What the **** is going wrong with my system?

Chris G. · 17. Januar 2016

Today I ran iperf...

Code

iperf -s

on the server

Code

iperf- c 192.168.188.23 -i 2

on the client

Code

------------------------------------------------------------
Client connecting to 192.168.188.23, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[  3] local 192.168.188.26 port 39143 connected with 192.168.188.23 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 2.0 sec   189 MBytes   793 Mbits/sec
[3]  2.0- 4.0 sec   187 MBytes   786 Mbits/sec
[  3]  4.0- 6.0 sec   183 MBytes   767 Mbits/sec
[  3]  6.0- 8.0 sec   184 MBytes   774 Mbits/sec
[  3]  8.0-10.0 sec   187 MBytes   783 Mbits/sec
[  3]  0.0-10.0 sec   931 MBytes   780 Mbits/sec

Alles anzeigen

There is no sign of a bottleneck, and still the connection goes bananas with big files...
And still my PC can not access my OMV shares...

ryecoaaron · 17. Januar 2016

Samba has quite a bit more overhead than iperf but it shouldn't be that slow. Can you access OMV shares from your pc by using its IP address?

Chris G. · 17. Januar 2016

I now updated Samba to 4.1.17.
Now my Laptop is also unable to connect to the shares...
No, then Chrome opens with the web-interface.

Chris G. · 17. Januar 2016

I made a clean install.
Now my Laptop can connect again!
Still my PC can't. It's Samba 3.6.6 again and the Write-Speed Problem still exists...

ryecoaaron · 17. Januar 2016

It shouldn't open chrome when trying to connect to the share via IP. Open windows explorer and type \\omv-ip-address
If the laptop can connect, then there is something wrong with your pc. Did you reboot?

hansher · 17. Januar 2016

Hello,

I have exact the same Problem with (Odroid xu4 with OMV). After 1-2 sec. the writing speed to omv drops to max. 10 MByte / sec (smb/cifs) to a usb3 2,5 inch HD. I did not alter anything to the OMV.

update:
I have re-installed omv on xu4. Then speed on the external 2,5 inch HDD is ok (70 MByte/sec). As soon as I change in OMV the HDD settings Powermanagement, Spindown-Time the write speed goes down to 10 Mbyte/sec. Even if I deactivate everything, the speed does not come back and remains at 10 MByte.

Hm.
Hans

Chris G. · 18. Januar 2016

Hi there,

well if that solves the write speed problem, then I will reinstall OMV the third time...
And I will never touch the performace options again!

Yep, I already thought, that there must be some setting wring with my PC, I will now have to try out which one...

I will get back to you, when I tested it out.

Chris G. · 20. Januar 2016

Hi,
I reinstalled everything and did not touch any disk performance option.
I now get 70 MB/s write speed without Samba performance tuning.
I would like this thread to be marked as solved although I still can not access the shares with my PC.
Thank you very much!

Reed · 20. Januar 2016

I had seen that type of initial burst of speed and then a drop in speed for my system as well. It was similar to the topic here:
Bottleneck for Samba after a few seconds of transfer. Network & Sata tested

For me, uninstalling SMB 1.0 quote "If you using a Windows, turn off SMB 1.0/CIFS File Sharing Supportoption under Turn Windows features on or off" made it a lot more constant. I now get a very constant 100-110 MB/s transfer rate with Samba.

I couldn't ever figure out why having SMB 1.0 installed messed with the transfer rates. I did about half a dozen Google searches to see if this was a known topic, but I never found anything about it. But it definitely was a measurable effect for me. If reinstalled SMB 1.0 the behavior (dropping speed after a few seconds) returned, uninstall again and it would disappear again. I tried setting the minimum protocol to SMB 2 in the conf file, but it didn't have the same effect, which I thought was strange because it should have been about equivalent in what it was trying to accomplish.

My final configuration is:
- I installed Samba 4.16 (make sure you install the vfs modules as well if you use the recycle bin otherwise you won't be able to access your drives => 'apt-get install samba-vfs-modules'). I upgraded Samba for another reason as I was debugging an issue with Samba freezing my network stack. But I also like having SMB3 available from 4.16.
- I use 'min protocol = SMB2' even though I didn't see much effect.
- I uninstalled SMB 1.0 from Windows. Biggest effect.

Reed · 20. Januar 2016

Zitat von Chris G.

I now updated Samba to 4.1.17.
Now my Laptop is also unable to connect to the shares...
No, then Chrome opens with the web-interface.

What exactly was the behavior?
- Were you able to see/browse a list of the shares at the IP address, but not enter the shares?
- Did you have recycle bin enabled on those shares?

The only problem I ran into in installing Samba 4.16 was I had recycle bin enabled for the shares, but I hadn't installed the vfs modules that recycle bin relies on. So it would try to find the recycle bin vfs upon trying to access the drive and entry would fail because it couldn't find the vfs file. Easily fixed with "apt-get install samba-vfs-modules".

Chris G. · 20. Januar 2016

Oh that also is a nice tip!
I just deinstalled SMB 1 on both my PC and my Laptop.
I upgraded to Samba 4.1.17:

Code

root@SABRE:~# smbstatus
Samba version 4.1.17-Debian
PID     Username      Group         Machine
-------------------------------------------------------------------
Service      pid     machine       Connected at
-------------------------------------------------------
No locked files

I use 'min protocol = SMB2'.
I also installed the vfs-modules.

If I go to "Network" in the explorer it lists my PC, my Laptop and my Switch/Access Point, but not the OMV-machine.

I believe that this has something to do with Windows, but I have no idea whatsoever...

Reed · 20. Januar 2016

What does it say if you type the IP address and sharename in a windows explorer window? (substitute in your ip address and sharename)

\\192.168.1.4\sharename

I always use static IP address for less headache.

Write speed to OMV dropping after 1 sec to 10 MB/s

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