SATNOGS-Client on UBUNTU doesn't decode data

as I want to migrate my Client from RASPI4 to virtual UBUNTU to improve performance , I’ve set up 2 identical stations on these platforms, with the same SDR and the same antenna input signal. The waterfalls from the two stations look very similar, but the UBUNTU station doesn’t decode data.
For example there are the observations #8999140 on UBUNTU (0 packets decoded) and the #8996161 on RASPI4 (56 packets decoded). The logfile doesnt show anything special. Any ideas what could be different with UBUNTU? Might there be something wrong with the gr setup?

EDIT: thing become even more strange! after rebooting UBUNTU the next pass of UVSQ-SAT was sucessfully decoded by the UBUNTU client, but this time the RASPI station failed (it never failed before for many months).
Feb 07 11:02:39 raspberrypi satnogs-client[368]: [INFO] Opening Generic RTL2832U OEM :: 00000001…
Feb 07 11:02:39 raspberrypi satnogs-client[368]: Found Rafael Micro R820T tuner
Feb 07 11:02:39 raspberrypi satnogs-client[368]: [R82XX] PLL not locked!
Feb 07 11:02:39 raspberrypi satnogs-client[368]: [INFO] Using format CF32.
Feb 07 11:02:39 raspberrypi satnogs-client[368]: Allocating 15 zero-copy buffers
Feb 07 11:02:49 raspberrypi satnogs-client[368]: cb transfer status: 2, canceling…
Feb 07 11:11:51 raspberrypi satnogs-client[368]: Resetting device…
Feb 07 11:11:53 raspberrypi satnogs-client[368]: gr-satellites: Observation: 8996162, Norad: 47438, Name: UVSQ-SAT, Script:
Feb 07 11:11:53 raspberrypi satnogs-client[368]: gr-satellites: Stopping observation 8996162
Feb 07 11:11:53 raspberrypi satnogs-client[368]: - ERROR - Waterfall data array is empty

Can there be any interference of two clients in the same subnet?

Lets see if I can help you in the right direction based on the little you have shared on the virtual Ubuntu.

As Ubuntu isn’t officially supported, what install description did you use to get all the packages/modules working and configured all the integrations?

My best ques is that although you can see the RTL device Found Rafael Micro R820T tuner you are not allowed to connect to it or that another kernel module is still using it, and blocking the SatNOGS client from using it.

Some tests you can try:

rtl_test -d 0 and please share the output.

If you run rtl_sdr -f 435e6 -d 0 - do you get streaming IQ data on the screen?

Please share as much information as possible to solve this.

Thank you very much for your quick response. I’ve setup UBUNTU 20.04 as described in the Satnogs-Wiki. Everything went perfectly without any problems.
There was only one initial problem, that the OS lost the USB-device of the stick, but it seems I have found the reason and turned of the power-save mode of the USB-HUB on the host side.
The other problem described above appears to be a little bit fuzzy. Sometimes it works, sometimes not, after reboot again…
Would be nice, when the client would run on the PC, because my PI4 is at the limit of its power.
Here the requested debug-info:

stefan@ubuntu:~$ rtl_test -d 0
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000001

Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6
[R82XX] PLL not locked!
Sampling at 2048000 S/s.

Info: This tool will continuously read from the device, and report if
samples get lost. If you observe no further output, everything is fine.

Reading samples in async mode…
Allocating 15 zero-copy buffers
lost at least 112 bytes

This one seems to have failed in some way …

Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000001

Using device 0: Generic RTL2832U OEM
rtl_sdr, an I/Q recorder for RTL2832 based DVB-T receivers

Usage: -f frequency_to_tune_to [Hz]
[-s samplerate (default: 2048000 Hz)]
[-d device_index (default: 0)]
[-g gain (default: 0 for auto)]
[-p ppm_error (default: 0)]
[-b output_block_size (default: 16 * 16384)]
[-n number of samples to read (default: 0, infinite)]
[-S force sync output (default: async)]
filename (a ‘-’ dumps samples to stdout)

The latest news: the latest pass of UVSQ-SAT was decoded very well by the UBUNTU-client, far better than by Raspi4 this time. There was only one thing I changed. The receiver gain from 49 to 48, because when I entered your command I saw, that 49 was not listed only 49.7 or 48. I dont know if this should matter in UBUNTU, in RASPBIAN it doesnt. Anyway, I’ve scheduled a view observations for the night and we’ll se in the morning, what happened.

After one more day of testing, I could identify the root cause of the problem. The reason is, that the VM still loses connection to the sdr-stick. The stick is listed “connected” in the VM, but in fact it is connected to the host. So turning off the power-save-mode of the usb-hub didnt help. after disconnect/reconnect of the usb-device in VM everything is fine again, rtl_test and rtl_sdr (i had to specify an output file) running very well. So finally we can say, the issue is related to the VMWARE-player and the way it manages USB-devices. Something seems to go to sleep over night

In the past I tried a couple of Virtualization solutions: VMware, Virtualbox and KVM all have issues with usb connections. Lowering the sample rate to 1.024e6 did help in some cases.

If your Virtualization solution supports pass through, you can try this and see if the usb device is working in a more reliable and performand way

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Ok, thanks for your suggestions. That sounds for me as it would be better not to use VM at all for this purpose. I’ll spend some addidional time on this, but when that solution keeps refusing to work stable, i will put the UBUNTU on an old Notebook.
Thanks, 73

Found an interesting fact in the Staus-LOG. The station goes offline at exactly the same time every day. It is NOT the internet-connection, because all other stations stay connected. Doing additional investigations on this phenomena …