Slow read speed from array


UnKwicks

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Hi guys

 

I read a lot topics here about slow read/write performance with SMB but I did not find something like mine or any solution there helped me.

So I start this thread.

 

I switched recently from QNAP to my new unraid build. and I am testing performance right now.

First some facts:

- I use macOS 10.15.5 as client OS

- I have a 12 TB Parity and a 12 TB Array Disk (WD red)

- I have SSD cache but not enabled for this share / this test

- I use unraid 6.8.3

- I test to copy a 2.5 GB image file.

- QNAP NAS and unraid server are connected with a 1 GB ethernet.

- My SMB config:

veto files = /._*/.DS_Store/
#unassigned_devices_start
#Unassigned devices share includes
   include = /tmp/unassigned.devices/smb-settings.conf
#unassigned_devices_end
#disable SMB1 for security reasons
[global]
   min protocol = SMB2

 

Write speed: 

UNRAID: Copying the file to my unraid Server takes about 55 seconds

QNAP: Copying the file to my QNAP NAS takes about 65 seconds

 

So no problems here.

 

Read speed:

First I had poor performance for directory listing when browsing the share. so I set "Enhanced macOS interoperability = yes" and this helped a lot.

 

UNRAID: Reading the file from my unraid server takes 2 min 48 sec.

QNAP: Reading the file from my QNAP NAS takes 58 sec

 

So reading performance from my unraid server is pretty poor in comparison to my old QNAP.

What am I missing here? Some ideas why reading is so slow  while writing is fast?

 

Thanks!

Edited by UnKwicks
not SMB related so I put SMB out of thread title
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I did another measure:

Activity Monitor in Mac OS shows me a max. of:

  • 14 MB / sec when reading a file from my unraid SMB share.
  • 130 MB / sec when writing a file to my unraid SMB share.

Any idea why reading is so slow is appreciated. It seems not to be an issue with my Mac because reading and writing to my QNAP NAS is fast (see first post)

 

Edit: I did some more tests with iperf.

Mac as client --> Unraid as server

[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec   597 MBytes   501 Mbits/sec                  sender
[  4]   0.00-10.00  sec   596 MBytes   500 Mbits/sec                  receiver

Unraid as client --> Mac as server

[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec   164 MBytes   137 Mbits/sec    0             sender
[  5]   0.00-10.00  sec   162 MBytes   136 Mbits/sec                  receiver

 

Edited by UnKwicks
added iperf results
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Thanks a lot for you help.

7 hours ago, Benson said:

it usually network issue, pls ensure both end NIC MTU setting are match

MTU is set to default 1500.

 

7 hours ago, Benson said:

Does using WiFi in one end ?

Yes the Mac is on Wifi but for my connection to the QNAP NAS as well. Reading from unraid is about 3x slower in this scenario than reading from QNAP.

 

7 hours ago, Benson said:

For SMB, pls try 'Disable SMB Signing on OS X'

I use macOS 10.15.5. SMB signing is disabled by default on 10.13.4 and higher.

 

7 hours ago, Benson said:

Pls also search post for how to tweak for increaee MAC OS SMB performance with Unraid.

I read through each post in this forum I found and googled for several hours. Sadly most posts are 2 years old or older and describe slow speeds in general. I have slow speeds only for reading. As stated in my first post I set "Enhanced macOS interoperability = yes" and this helped a lot. But still having this bad reading speed for a file transfer (dir listing speed is ok now)

Is there a special tweak or thread you are talking about?

Edited by UnKwicks
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Ok, I guess my issue is not SMB related as I thought before.

I did some more iperf testing.

Let me add the following before I post the results:

  • Using LAN read and write speed is good
  • Issue seems only to appear using wifi on client but then only with unraid.

So I did iperf having my MacBook connected via Wifi and Unraid as well as QNAP via LAN.

 

QNAP (LAN) iperf client --> MacBook (Wifi) iperf server:

[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec   556 MBytes   466 Mbits/sec    0             sender
[  5]   0.00-10.00  sec   555 MBytes   466 Mbits/sec                  receiver

Unraid (LAN iperf client --> MacBook (Wifi) iperf server:

[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec   125 MBytes   104 Mbits/sec    0             sender
[  5]   0.00-10.00  sec   123 MBytes   103 Mbits/sec                  receiver

MacBook (Wifi) iperf client --> QNAP (LAN) iperf server:

[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec   518 MBytes   434 Mbits/sec                  sender
[  4]   0.00-10.00  sec   517 MBytes   433 Mbits/sec                  receiver

MacBook (Wifi) iperf client --> Unraid (LAN) iperf server:

[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec   493 MBytes   413 Mbits/sec                  sender
[  4]   0.00-10.00  sec   492 MBytes   412 Mbits/sec                  receiver

 

So only sending from Unraid to my MacBook is slow!

MTU on all devices is 1500. 

 

I attached my diagnostics zip if this helps.

 

 

TOWER-diagnostics-20200920-1654 2.zip

Edited by UnKwicks
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  • 5 months later...

Same issue with a MBP running 10.15. I saturate a 2.5 Gbe connection when writing to the array (cache drive), but READING from it to my MBP NVME drive will only give me 300 Mb/s (LAN on both sides running through a 10Gbe SFP+ switch).  I've done most of the same troubleshooting as you have. Just here to say you're not alone.  I will post here if I find my answer.

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  • 5 weeks later...

HI, Can anyone here help us out.
Writing to the unraid raid array is super fast, 2.5g 
but reading from it is abysmal, like 20-30 mb/s 
How can I overcome this? what can I do to make reading from the array as fast as the drive speed which should be 120mb/s
Thanks a ton

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Note that slow iperf results can also be caused by some OS issue with the source computer, basically you need to test all the things involved in the network one at a time, NICs, cables, switch, source computer until you find the culprit, also in your case it's with WiFi, that's notoriously unreliable for consistent speeds, first thing to try is cabled connection.

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On 4/10/2021 at 3:55 AM, JorgeB said:

Start by running a single stream iperf test.

I did, 
I should say this, So my server has a 10gb nic connected to a 10gbe switch which my mac is currently connected to. 
Now, the mac is on a 2.5gb nic ( it will soon be upgraded to a 10bge nic )(waiting on parts to arrive) 
running iperf from the mac to the server is 2.65gbs (which I can live with) translating this to aja or blackmagic speed test to 120-140MB write (which im ok with for now) 
running iperf from the server to the mac the speed is 232 mbs which translate to 20MB read from the server which I dont get why

I already set mtu to 9000 and nothing, ive tried about all the smb tweaks I can think of (except for link aggregation) 
 

Edited by Ralph456
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