writing speed consistently at around 60MB/s

[iamsammajor]

Hi all,

 

as mentioned above I am struggling with low write performance to my cache SSD over Lan.

everything else is running perfectly, my download speed from the share is approx 100MB/s (I have no idea on how to get the speed test apart from copying to and downloading from, any suggestion on alternate method is appreciated) 

 

• xeon e3-1220 v3
• 16gb DDR3 Ram
• 1x 3t HDD
• 1x 120 SSD for cache,

 

dianostic file is attaced, Any idea? 

 

 

samsbay-diagnostics-20200826-1116.zip

[JorgeB]

Is the speed better if you copy directly to the array?

[Iker]

You could try with "DiskSpeed" from CommunityApp or dd command (https://www.cyberciti.biz/faq/howto-linux-unix-test-disk-performance-with-dd-command/)

[Frank1940]

Also test transfer speeds with very large files > 20GB in your case.   File overhead can be a problem even with using ssd's.  (Your CPU is not exactly a barn burner these days.)  You have 16GB of memory and it looks like you might have a considerable of RAM available as a cache for writes.  You should really be seeing a initial burst of write speeds at the 100(+)MB/s rate and then a dropback after the RAM cache fills up. 

[iamsammajor]

12 hours ago, johnnie.black said:

Is the speed better if you copy directly to the array?

if cache is not enable, i getting a jummpy speed from 30-60MB up and down,

[iamsammajor]

8 hours ago, Frank1940 said:

Also test transfer speeds with very large files > 20GB in your case.   File overhead can be a problem even with using ssd's.  (Your CPU is not exactly a barn burner these days.)  You have 16GB of memory and it looks like you might have a considerable of RAM available as a cache for writes.  You should really be seeing a initial burst of write speeds at the 100(+)MB/s rate and then a dropback after the RAM cache fills up. 

i was using a 8gib movie to do the testing, i did wonder replacing the CPU would help, but didnt see CPU usage ramp up that much when i was copying the file.

[iamsammajor]

12 hours ago, Iker said:

You could try with "DiskSpeed" from CommunityApp or dd command (https://www.cyberciti.biz/faq/howto-linux-unix-test-disk-performance-with-dd-command/)

try to do brenchmarking on the drive?

[JorgeB]

10 hours ago, iamsammajor said:

if cache is not enable, i getting a jummpy speed from 30-60MB up and down,

That suggests a network or source problem, without parity you should be able to write to the array faster than that, start by running iperf.

[iamsammajor]

13 hours ago, johnnie.black said:

That suggests a network or source problem, without parity you should be able to write to the array faster than that, start by running iperf.

i am learning how to run iperf, will report back result. thanks for helping

[iamsammajor]

14 hours ago, johnnie.black said:

That suggests a network or source problem, without parity you should be able to write to the array faster than that, start by running iperf.

i have this result.

[JorgeB]

Close enough, do you have another source computer you can test the transfer with?

[iamsammajor]

On 8/28/2020 at 6:53 PM, johnnie.black said:

Close enough, do you have another source computer you can test the transfer with?

I borrow my friend’s laptop. It’s iperf result is close and do have the write speed of 110MB/s. I tried update the nic driver but didn’t make any difference. 
it is isolated to my pc end but I’m not too sure what else can be done.

[JorgeB]

At least you now know where the problem is, if you can try a different NIC on the PC, it can also be an OS issue, re-install might help.

[Frank1940]

Be sure you swap to a different port on the switch that the PC is connected to .   You should also power cycle the switch.  These things all have a SOC chip in them and a reboot often clear problems.

Edited August 30, 2020 by Frank1940

[iamsammajor]

8 hours ago, johnnie.black said:

At least you now know where the problem is, if you can try a different NIC on the PC, it can also be an OS issue, re-install might help.

 

8 hours ago, Frank1940 said:

Be sure you swap to a different port on the switch that the PC is connected to .   You should also power cycle the switch.  These things all have a SOC chip in them and a reboot often clear problems.

 will try both, and keep you guys posted, thanks for your help