Re: [Dorset] Can my system run out of memory if my program continuously O/Ps messages to the shell?
On Tuesday, 11 April 2017 13:23:36 BST Patrick Wigmore wrote: > On Tuesday, 11 April 2017, at 12:16:44 BST, Terry Coles wrote: > > Thanks. Now I can focus on the overheating. We were trying to > > avoid any holes in the case for ventilation. > > I don't want to jinx it, but you might find you have to drill > some drainage holes anyway. Water is a sly opponent! I'd keep an > eye on that. You may be right, but we'll only be running during the summer months, when the outside air temp is reasonably high. > If it's a totally sealed box, I would be inclined to at least put > some dessicant in there to absorb the moisture that's trapped in > the air inside, otherwise you might get condensation issues from > the outside temperature fluctuations. It is pretty much sealed. > > It looks like I need to put a fan inside to help natural > > convection to shift the air from the Pi to the heatsink. > > Is there a heatsink on the Pi's CPU? If there isn't, that would > be fairly easy to add and would probably go a long way, if it is > a thermal issue. Full complement of heatsinks on all three chips. CPU temp is normal. -- Terry -- Next meeting: Bournemouth, Tuesday, 2017-05-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] Can my system run out of memory if my program continuously O/Ps messages to the shell?
On Tuesday, 11 April 2017 13:00:29 BST Ralph Corderoy wrote: > Do you know what's generating the heat? Infra-red thermometer or > camera? Can anything be added that would conduct the heat from those to > the case or the internal heatsink? At this stage, I'm not completely certain that heat is the problem. I'm going in to the WMT in a few minutes, so I'll be interested to learn if the problem has been as bad since we've had this cold wind. Also, I intend to run the system out of the case for a few days, to see if we still have an issue. (That would also eliminate (or rather show up) my other theory; interference from the lighting. However, I'm not sure how interference would manifest itself only after the system has been running for some time.) As for an Infra-red thermometer or camera; no, we don't have one. It's a good idea though. Perhaps I should invest in a Pi NoIR (http://www.raspberrypi-spy.co.uk/2013/10/pi-noir-infrared-camera-module-for-raspberry-pi/) to allow me to do the tests :-) -- Terry -- Next meeting: Bournemouth, Tuesday, 2017-05-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] Can my system run out of memory if my program continuously O/Ps messages to the shell?
On Tuesday, 11 April 2017, at 12:16:44 BST, Terry Coles wrote: > Thanks. Now I can focus on the overheating. We were trying to > avoid any holes in the case for ventilation. I don't want to jinx it, but you might find you have to drill some drainage holes anyway. Water is a sly opponent! I'd keep an eye on that. If it's a totally sealed box, I would be inclined to at least put some dessicant in there to absorb the moisture that's trapped in the air inside, otherwise you might get condensation issues from the outside temperature fluctuations. > It looks like I need to put a fan inside to help natural > convection to shift the air from the Pi to the heatsink. Is there a heatsink on the Pi's CPU? If there isn't, that would be fairly easy to add and would probably go a long way, if it is a thermal issue. Patrick. -- Next meeting: Bournemouth, Tuesday, 2017-05-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] Can my system run out of memory if my program continuously O/Ps messages to the shell?
Hi Terry, > We were trying to avoid any holes in the case for ventilation, so > cooling depends on internal circulation of the air to move the heat > from the hot-spots to a finned heatsink on the inside of the case. Do you know what's generating the heat? Infra-red thermometer or camera? Can anything be added that would conduct the heat from those to the case or the internal heatsink? Cheers, Ralph. -- Next meeting: Bournemouth, Tuesday, 2017-05-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] Can my system run out of memory if my program continuously O/Ps messages to the shell?
On Tuesday, 11 April 2017 11:40:05 BST Ralph Corderoy wrote: > They take buffers and cache out of the equation. 785612 / 16204 = 48 so > you can withstand growth at that rate for quite a few multiples of your > monitoring period, if it's linear. Thanks. Now I can focus on the overheating. We were trying to avoid any holes in the case for ventilation, so cooling depends on internal circulation of the air to move the heat from the hot-spots to a finned heatsink on the inside of the case. The case BTW is an old 7.62 mm Ammo Box :-) The idea is that the heatsink transfers heat from the air to the metal wall of the case. It looks like it may not be working as planned. It looks like I need to put a fan inside to help natural convection to shift the air from the Pi to the heatsink. If that doesn't work, I'll have to put in some vents, but that will let damp air in -- Terry -- Next meeting: Bournemouth, Tuesday, 2017-05-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] Can my system run out of memory if my program continuously O/Ps messages to the shell?
Hi Terry, > My interpretation of that is that free memory has declined (fairly > rapidly), but the values for shared, buffers and cached have increased > too. Presumably, that memory will be released by the OS when needed? Buffers and cache, yes. These are the interesting lines from your two runs. > used free > -/+ buffers/cache: 145912 801816 > -/+ buffers/cache: 162116 785612 16204 -16204 They take buffers and cache out of the equation. 785612 / 16204 = 48 so you can withstand growth at that rate for quite a few multiples of your monitoring period, if it's linear. Cheers, Ralph. -- Next meeting: Bournemouth, Tuesday, 2017-05-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
