This machine was being our router, it is the only machine aside from Inuvik that has more than one Intel NIC.  So presently Iglulik is playing router but it only has one Intel and one Realtek interface, the Realtek is supposed to  be capable of 100, 1G, and 2.5G but the Linux drivers for it are seriously broken and only function at 100mb/s hence we are at 1/10th our normal network speed.

     The newly broken machine houses some shell servers and all the private virtual machines, and it died too rapidly to copy any data off.  This is the machine that I just replaced the failed drive in the other day.  There are indications that it may just be a bios battery, it will not save settings nor let me load defaults.  So I’m going to start by changing that.  If that does not fix it, then I am going to put that drive into my workstation, transfer all the files onto a 2TB flash drive and take them back to the co-lo to load onto the remaining machines, also stop by RE-PC and pick up another Intel NIC card.  And then go from there.

     Right now the following shell servers are operational:

        popos, rocky, fedora, debian, mxlinux, and manjaro.

     Innuvik is back in service.  I fixed the cable connector by epoxying the 4-pin to the 20-pin effectively making it a 24 pin connector so the latch on the 20 pin section holds all in.  I no longer get intermittent power when I move the cable around.

     I discovered that about a penny sized area of air gap between the CPU heat spreader and the cooler had developed and so regooped the whole thing but this time I did not have the higher quality compound.  Still at 4.8 Ghz under the most extreme CPU torture test I have it maxed at 82C and averaged about 70C, with the better compound it will max at about 62C when there are no gaps, but this is adequate.

coretemp-isa-0000
Adapter: ISA adapter
Package id 0: +33.0°C (high = +76.0°C, crit = +86.0°C)
Core 0: +30.0°C (high = +76.0°C, crit = +86.0°C)
Core 1: +29.0°C (high = +76.0°C, crit = +86.0°C)
Core 2: +29.0°C (high = +76.0°C, crit = +86.0°C)
Core 3: +31.0°C (high = +76.0°C, crit = +86.0°C)
Core 4: +33.0°C (high = +76.0°C, crit = +86.0°C)
Core 8: +30.0°C (high = +76.0°C, crit = +86.0°C)
Core 9: +31.0°C (high = +76.0°C, crit = +86.0°C)
Core 10: +28.0°C (high = +76.0°C, crit = +86.0°C)
Core 11: +31.0°C (high = +76.0°C, crit = +86.0°C)
Core 16: +31.0°C (high = +76.0°C, crit = +86.0°C)
Core 17: +30.0°C (high = +76.0°C, crit = +86.0°C)
Core 18: +31.0°C (high = +76.0°C, crit = +86.0°C)
Core 19: +30.0°C (high = +76.0°C, crit = +86.0°C)
Core 20: +32.0°C (high = +76.0°C, crit = +86.0°C)
Core 24: +31.0°C (high = +76.0°C, crit = +86.0°C)
Core 25: +30.0°C (high = +76.0°C, crit = +86.0°C)
Core 26: +29.0°C (high = +76.0°C, crit = +86.0°C)
Core 27: +30.0°C (high = +76.0°C, crit = +86.0°C)

     This is what temps are looking like now, you notice there is only a 4C spread between the hottest and coolest cores, before that spread was 20C.

     So I would like to have the additional overhead but this should suffice for now.  I have a new power supply on order as this one is a little doggy and sags under load more than I would like.  The current supply is a 1000 watt Gigabyte supply, the replacement is a Phanteks 1200 watt which is a rebranded Seasonic, it’s has a 12-year warranty so at least financially if it dies it will be someone else’s problem.

     So I don’t know if this is going to fix the stability issues or not, but I did run it with the most extreme CPU torture test software I have at 4.8 Ghz all cores two threads per core for an hour before I took it back to the co-lo and no CPU errors.

     So back in service are roundcube.eskimo.com, friendica.eskimo.com, hubzilla.eskimo.com, and yacy.eskimo.com and with all these running full tilt CPU is still about 97% idle and I’m working on some additional new services.

     I was able to fix the existing power connector with epoxy, it no longer loses power if I wiggle it around.  And I took the CPU off and it definitely developed a bad air gap, almost a penny right in the middle of the heat spreader.  I could tell because the compound had dried up there.  The thermal grizzly extreme is a read color that turns a pink if it dries up so is very visually obvious.  I am putting it back together with some lesser quality paste because that’s all I have until the gets here, so I will change that and the power supply out at that time.  Going to switch from a Gigabyte 1000 watt to a Seasonic 1200 watt unit.  So I will do all of that about a week and a half from now when everything arrives.  I am going to let it burn in for a couple of hours and if it does not crash bring it back into the co-lo facility tonight.

     The above services will be down until some time Saturday evening.  This machine has been unstable and getting increasingly so.  It does have a heat issue which I will resolve when some new heat sink compound arrives, but even down clocked so it did not get too hot it was still crashing and sometimes when almost entirely idle.

     When I got it back at my home to work on, I discovered the ATX power cable was flaky, and I could make the entire motherboard lose power by just wiggling the cable.  This is probably introducing noise and unstable voltage to the CPU.

     I have ordered a replacement cable and it should be here Saturday.  There may be other issues but a bad power cable is definitely an issue so I will start by replacing it.

    Inuvik is running too hot.  This machine was running at 4.8Ghz small fft torture test 36 threads 2/threads per core before I brought it over to the co-lo but it is exceeding 96C now but only on a couple of cores.

     When you have a couple of cores running hot on a multi-core CPU but the rest are normal, this is usually indicative of an air bubble between the CPU and cooler so part of the heat spreader is not receiving cooling.  This is more pronounced with the i9-109×0 series of CPUs because the heat spreader is soldered to the die.  On most microprocessors there is thermal compound between the die and the heat spreader. This creates some diffusion that does not occur when the die is soldered to the heat spreader so any air bubbles are more critical.

     I’ve ordered some more Kryonaut Extreme which should get here between October 1st and 3rd, at which time we will pull the machine from the co-lo for a few hours to clean the CPU and heat sink and re-paste it.  I will perhaps be just a smiggin’ more generous with the paste this time.  I am stingy not because of cost but because no matter how conductive thermal paste is it is less conductive than the metals you are trying to transfer heat between so you want as thin of a layer as you can get away with, but the worst thermal paste is better than the best air so a little too much is less bad than not quite enough which appears to be the case presently.

     Between now and then I’ve reduced the speed of the machine from 4.8ghz to 4.4ghz and CPU voltage from 1.37 to 1.2v to reduce heat generation.  This will reduce performance by slightly less than 10%, but give it’s around 97% idle time on the CPU’s this should not be a problem and it’s only temporary.

     Right now this is more of an issue than it otherwise would be because there exists a bug in the kernel code when it writes to the MSR to change the CPU speed in response to excess temperature.  If this bug did not exist the machine would simply have automatically downclocked, but this is a current bug affecting these particular CPUs.

     When ice, the server that previously experienced the hard drive failure failed, I moved the network connection to another server, inuvik, but, I had been using ice because it is the only machine which has all Intel network interfaces.

     The other machines all have one Intel and one Realtek, thus to use them as a router requires the use of a Realtek NIC on those machines.  The device drivers for Realtek network interfaces under Linux have been dodgy, last time I had to do this we could not get the NIC to see carrier at 1gb/s so had to run at 100mb/s temporarily but this time it saw carrier fine and was stable for a week which is some kind of record.  But when I got to the co-lo the NIC was totally locked up.  Not even a reboot got it going, had to power cycle the machine.

     So now that ice has a new drive, the network connection is moved back to it and things should be stable (I know, famous last words).

     Last night I spent several hours fine tuning our newest machine, Inuvik, I was not able to get any faster CPU speeds, in fact I am running at 4.8Ghz now because I did find with some tests, notably long fft tests, it did show some instabilities even though in a weeks operation these have not manifested.

     But I was able to significantly improve memory performance from 2133Mhz to 3400 Mhz and on an 18 core CPU every memory cycle you can get is precious.

     I was also able increase the Mesh frequency slightly from 2.6Ghz to 2.8Ghz.  The mesh is similar to rings in lower core count CPUs, it is used to provide communications between the cores.  I don’t know how much traffic this actually is in a Linux environment so I don’t know to what degree this helps but every cycle one can get anywhere.

     Ok, after that I turned to kernel upgrades, and the last machine to upgrade was the one used for our router.  It had a drive that had previously shown some SMART errors but after running a diagnostic they went away and it behaved until last night.  Last night it absolutely would not boot.  Strangest damned thing, could read the drive, write the drive, but could not boot off of it.  I’ve never seen a drive failure cause this so I assumed a software issue and re-installed grub, re-installed kernels, re-built the initramfs system, and these are pretty much all the software components you should need to be able to boot but no go.  It would find and load grub but grub couldn’t find the kernel, very very odd.  I was so convinced this had to be software issue that I had to re-install 25 times to convince myself otherwise.  I finally stole one of the drives out of the RAID array and turned it into a new system disk, that worked.  But it does not have everything it needs and it’s not a healthy young pup itself.

     So for now I’ve moved the routing and all the virtual machines off this box.  At present the two services are down are the NIS master which means you can’t change your password or login shell at the moment, and a DNS server, but we have six so that isn’t going to seriously impair things.

     I have a new drive which I had purchased when the first drive started puking out SMART errors, and it also is a 7200 RPM drive with 4x the cache the old drive had.  At present I’m copying all the data off the failed drive to the drive I stole out of the RAID array to bring the machine back up, and then I’m go replace that old drive that has failed with the new one, recover any data I need for NIS and for the name server off that drive, then reformat and return it to the RAID array.

     I am working on a new video conferencing feature to add to our site shortly.  I tried to get another suite working but it depended upon a message protocol that we are not able to get to work.  This one uses infrastructure I am more familiar with so my chances are somewhat better.

     I am also looking at RustDesk as a possible replacement for Guacamole because the developers have really turned Guacamole into an unmaintainable disaster.  It really is oriented towards LDAP auth and our network isn’t, so that doesn’t work so well for us.

Our newest and most powerful server, Inuvik, is now restored to service. It is an i9-10980xe CPU with 256GB of RAM clocked at 4.9Ghz. The big  challenge to getting this operational was finding a motherboard that could reliably supply the enormous power requirements of this chip. While rated at a TDP of 165 watts, this with only a single core not clocked at more than 4.8Ghz and the remaining cores at a baseline of 3Ghz. All cores clocked at 4.9Ghz with a heavy load such as prime95/mprime #16 torture tests test #2, small fft, 36 processes (all 18 cores provide hyperthreading), it can draw 540 watts. With a CPU core voltage of 1.32 volts, this works out to 409 amps, a lot for a PCB trace to handle and in fact on the Asrock motherboard, it melted the solder at the CPU socket. Better boards handle this by having a number of planes dedicated to power and ground.

At this point, friendica, hubzilla, roundcube, yacy, and Manjaro shell server are all again operational. There are issues with Mastodon, an update left it broken and I’m still troubleshooting. Because of it’s refusal to run under a modern OS, I have Ubuntu 20.04 installed on a virtual machine that is then proxied to through the main machine via a private network. Something seems to have gone afoul with this but I’m still trying to nail it down.