<html><head></head><body><div>Dear Amos,</div><div><br></div><div>There can be severall different possibilities:</div><div><br></div><div><br></div><div>First of all what is behind the high time difference. The DLS stores data in blocks with a start timestamp a count of blocks and a step time.If start + count * step > next start you will get this failure.</div><div><br></div><div>This can be caused by:</div><div>-RT properties, please check your system with cyclictest (rt-test suite)!</div><div>- Check your process cyclic time and execution time!</div><div>- What the normal system load of the system (top)?</div><div>- What is the normal IO load of the system (iotop)?</div><div>- Wat is your DLS blocksize. A small blocksize compared to your data frequency will cause high HDD load. My favorite settings freq/count blocks =1, means once a second a block is written per channel.</div><div>- If you have a simulink based model, NTP sync will not be a problem, because there is an internal time controller in the model. </div><div><br></div><div><br></div><div>Best regards</div><div><br></div><div>Andreas</div><div><br></div><div><br></div><div>Am Freitag, dem 17.03.2023 um 15:56 +0000 schrieb Merkel, Amos:</div><blockquote type="cite" style="margin:0 0 0 .8ex; border-left:2px #729fcf solid;padding-left:1ex"><div>Hi,<br></div><div><br></div><div>Thanks for the hint! Both DLS and the control job run locally on the same machine, so I expect they are using the same time source. I should have mentioned that in my first post, sorry. <br></div><div><br></div><div>However, my ntp was indeed not synchronised, as I recently turned it off as part of my troubleshooting. I did not notice any impact from turning it off on system level. <br></div><div>I turned it on again now, but do not expect a change in behaviour, as it should have been running when the errors first occurred. <br></div><div><br></div><div>Is there an active synchronisation of the time beyond the system clock? <br></div><div><br></div><div>Thank you & all the best<br></div><div>Amos<br></div><div><br></div><div>-- <br></div><div>Amos Merkel, M.Sc.<br></div><div>Gruppenleiter<br></div><div>Digitalisierung <br></div><div><br></div><div>ifas – Institut für fluidtechnische Antriebe und Systeme<br></div><div>RWTH Aachen University<br></div><div>Campus-Boulevard 30<br></div><div>52074 Aachen<br></div><div><br></div><div>Tel: +49 241 80-47737<br></div><div>Fax: +49 241 80-647712<br></div><div><br></div><div><a href="http://www.ifas.rwth-aachen.de">www.ifas.rwth-aachen.de</a> | Twitter | Facebook | YouTube | LinkedIn<br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div>-----Ursprüngliche Nachricht-----<br></div><div>Von: Sebastien BLANCHET <<a href="mailto:blanchet@iram.fr">blanchet@iram.fr</a>> <br></div><div>Gesendet: Freitag, 17. März 2023 15:38<br></div><div>An: Merkel, Amos <<a href="mailto:Amos.Merkel@ifas.rwth-aachen.de">Amos.Merkel@ifas.rwth-aachen.de</a>>; <a href="mailto:etherlab-users@etherlab.org">etherlab-users@etherlab.org</a><br></div><div>Betreff: Re: [Etherlab-users] Data loss in DLS<br></div><div><br></div><div>Hi,<br></div><div><br></div><div>Could you check that<br></div><div>- DLS and the data sources are synchronized with NTP<br></div><div>- your NTP server works<br></div><div><br></div><div>-- <br></div><div>Sebastien BLANCHET<br></div><div><br></div><div><br></div><div>On 17/03/2023 14:56, Merkel, Amos wrote:<br></div><blockquote type="cite" style="margin:0 0 0 .8ex; border-left:2px #729fcf solid;padding-left:1ex"><div>Hi everyone,<br></div><div><br></div><div>we are experiencing weird data losses on the DLS. Everything works as <br></div><div>expected for a couple of hours. Then, suddenly, there is a message in <br></div><div>the logs from dlsd_logger declaring an unexpected high time difference <br></div><div>in a number of channels followed by a message that the msr protocol was <br></div><div>reset by the peer and dls stops logging with error code -2. Logging is <br></div><div>continued after the preset 30 seconds, but typically crashes again <br></div><div>shortly after.<br></div><div><br></div><div>I am quite at loss how to proceed, there is nothing apparently wrong – <br></div><div>the same system set-up has worked up to now, there is nothing unusual in <br></div><div>the logs and system load (disc, cpu, network, ram) appears normal. The <br></div><div>error appears on several systems, the only common thing appears to be a <br></div><div>certain hardware configuration (certain somewhat older fujitsu <br></div><div>desktops). Unfortunately, I do not have enough other hardware at hand to <br></div><div>really support that theory.<br></div><div><br></div><div>We work with openSUSE and installed our etherlab environment from the <br></div><div>science:EtherLab repository using the generic network driver. We see the <br></div><div>error on 15.2 and 15.3 systems, but haven’t managed to check 15.4 yet.<br></div><div><br></div><div>Has anybody experienced similar behaviour before and has a hint on <br></div><div>possible causes or fixes?<br></div><div><br></div><div>All the best,<br></div><div><br></div><div>Amos<br></div><div><br></div><div>-- <br></div><div>Amos Merkel, M.Sc.<br></div><div>Group leader<br></div><div>Digitalization<br></div><div><br></div><div>ifas – Institute for Fluid Power Drives and Systems<br></div><div>RWTH Aachen University<br></div><div>Campus-Boulevard 30<br></div><div>52074 Aachen<br></div><div><br></div><div>Tel: +49 241 80-47737<br></div><div>Fax: +49 241 80-647712<br></div><div><br></div><div><a href="http://www.ifas.rwth-aachen.de">www.ifas.rwth-aachen.de</a> <<a href="http://www.ifas.rwth-aachen.de/">http://www.ifas.rwth-aachen.de/</a>>| Twitter <br></div><div><<a href="https://twitter.com/IFAS_RWTH">https://twitter.com/IFAS_RWTH</a>>| Facebook <br></div><div><<a href="https://www.facebook.com/IFAS-Institut-f%C3%BCr-fluidtechnische-Antriebe-und-Steuerungen-260714043957873/">https://www.facebook.com/IFAS-Institut-f%C3%BCr-fluidtechnische-Antriebe-und-Steuerungen-260714043957873/</a>>| YouTube <<a href="https://www.youtube.com/channel/UC0vIq8jtra8E_--Sx8DALkQ">https://www.youtube.com/channel/UC0vIq8jtra8E_--Sx8DALkQ</a>>| LinkedIn <<a href="https://www.linkedin.com/company/ifas-rwth/">https://www.linkedin.com/company/ifas-rwth/</a>><br></div><div><br></div><div>**<br></div><div><br></div><div> <br></div><div><br></div><div><br></div></blockquote><div><br></div></blockquote><div><br></div><div><span></span></div></body></html>