It was on old 3.5" drives a long time ago, before anything fancy was ever built into the drives. It was in a seriously rough working environment anyway, so we saw a lot of failed drives. If strange experiments didn’t work to get the things working, mainly for lulz, the next option was to see if a sledge hammer would fix the problem. Funny thing… that never worked either.

I used to take failed drives while they were powered on and kinda snap them really with a fast twisting motion in an attempt to get the arm to move or get the platters spinning.

It never worked.

Did you get bad sectors? Weird things can absolutely happen but having sectors marked as bad is on the exceptional side of weird.

Maybe? Bad cables are a thing, so it’s something to be aware of. USB latency, in rare cases, can cause problems but not so much in this application.

I haven’t looked into the exact ways that bad sectors are detected, but it probably hasn’t changed too much over the years. Needless to say, info here is just approximate.

However, marking a sector as bad generally happens at the firmware/controller level. I am guessing that a write is quickly followed by a verification, and if the controller sees an error, it will just remap that particular sector. If HDDs use any kind of parity checks per sector, a write test may not be needed.

Tools like CHKDSK likely step through each sector manually and perform read tests, or just tells the controller to perform whatever test it does on each sector.

OS level interference or bad cables are unlikely to cause the controller to mark a sector as bad, is my point. Now, if bad data gets written to disk because of a bad cable, the controller shouldn’t care. It just sees data and writes data. (That would be rare as well, but possible.)

What you will see is latency. USB can be magnitudes slower than SATA. Buffers and wait states are causing this because of the speed differences. This latency isn’t going to cause physical problems though.

My overall point is that there are several independent software and firmware layers that need to be completely broken for a SATA drive to erroneously mark a sector as bad due to a slow conversion cable. Sure, it could happen and that is why we have software that can attempt to repair bad sectors.

I started looking into that and if the price is right, it’s not that far-fetched. (After all, I did get my ham radio license mainly so I could legally transmit up to 1000W in some cases…)

HVAC repair seems to be a lucrative business so it may be something to do on the side. The certification would be a great way to start that, actually.

Thanks for the additional info!

It is absolutely just more cost effective, safer and better piece of mind to just replace the breaker. I’ll take that route 99.99% of the time.

If you feel adventurous, there are a couple of ways to test that breaker without proper test equipment. The risks could be zero OR you blow your face off and burn your house down.

Find an open outlet at tap live to ground. This will produce some natural and organic indoor fireworks, but it should trip the breaker. If it doesn’t, there is a small risk of welding the wires together and creating a very strange short condition, turning that entire circuit into a new heat strip. (Free money!)

Find two 1800W space heaters and together, on the same circuit, they should trip the breaker as well. (Breakers should be rated to at least 1800W.) This is problematic as well and I’ll explain. There is something magical about space heaters as I have seen 2 or 3 run off of the same circuit before. I suspect that if a breaker is slowly warmed up due to heavy load it will change its characteristics, causing it to only trip at higher loads. (Absolute speculation on my part!) By default, I would replace the breaker if I saw that kind of load. Extended, and higer heat cycles will eventually damage the breaker.

Ctrl z

That is single most annoying and useful feature ever implemented into a track pad.

Ok. I won’t look at it then as there is no point in ruffling any feathers.

I love it when post titles give me the proper heads-up, actually.

This is fairly common with remote sensors. Some are perfect and exist in a perfect system, some do not. I am going to rattle off some of the first things that pop into my head…

Honestly, there are a thousand reasons that you could miss a data point every once in a while. Just looking at the chart, it is still sending a data block but the humidity just reported low for a second. Maybe the thermostat is not getting a data block and filling in the data based on its own clock.

Compare it to other data and see if the system turned on or off. Electronics can be sensitive to power drops and it wasn’t able to feed power to the part of the board that manages the sensor for a second. Maybe there is a condition where a capacitor gets fully discharged for a second and is pulling all current away from the sensor. (It’s usually an analog signal from sensors and maybe a measurement of resistance that translates to temperature or humidity. A voltage drop would significantly impact a reading.)

It could be a timing glitch with the code where it can’t read the sensor but builds the data block anyway. Depending on how the sensor works, it could be trying to compute the data the second it gets polled for data and it has nothing to give.

It could even be the wiring to the rest of the system. HVAC systems vibrate and a screw might be getting loose. It could be a cold solder joint, even. What is to commonality between the two thermostats that you had?

The list goes on. I have always treated sensor data as unreliable. Heck, I have a couple of CO2 sensors that do the same this as what you are seeing here. Every so often, the just report zero for a second.

Mesh protocols like zwave and zigbee aren’t 100% reliable. It could be local interference with the signal.

Without some extensive debugging and the willingness to disassemble your thermostat, just treat it as an annoyance.

Meh, I didn’t mean to hate on DHCP. It’s just a service I have learned to keep running all by itself somewhere in a dark corner of my network. DNS and DHCP are just services that I don’t like going down. Ever.

DHCP is a really stupid* service for the most part. Unless you are working with multiple subnets or have some very specific settings you need to pass to your clients, it’s probably not worth it to manage it yourself. I don’t want to discourage you though! Assigning static IP addresses by MAC can be extremely useful and is not always an option on routers. If you want static names and dynamic addresses, that is really where you need to manage both DNS and DHCP. It really depends on how and where you want names to be resolved and what you are trying to accomplish. (*stupid as in, it’s a really simple service. You want it simple because when DHCP breaks, you have other serious issues going on.)

Setting up your own DNS is worth its weight in gold. You can put it just about anywhere on your network (before your gateway, after, in China, whatever.) and your network won’t even know the difference if setup correctly. You can point BIND at the root servers and bypass your ISP completely if you want. ISP DNS services suck ass, so regardless of you resolve yourself, or forward all name queries to your anon DNS server of choice you have a really decent level of control on your network. It is the service to learn if you want to keep an eye on where your network wants to talk.

Your Unifi USG must play nice with your own server, by the laws of DNS. There may be some nuances when it comes to internal protocols like WINS, but other than that, it should be just fine.

I would setup a simple VM somewhere first, to answer your actual question. It’s good practice to keep core services isolated on their own, dedicated instances. This is to speed up recovery time and minimize down time. Even on your home network, DNS and DHCP are services you do not want going down. It’s always a pain when they do go down.

Ditto. I was in an unlucky block of dynamic IPs from my ISP once. Not only was sending or receiving email out of the question, my IP addresses were somehow part of firewall blacklists as well. I couldn’t get to banks at all and tons of random places were just dropping my traffic. It was a serious pain.

Just to confirm, I say gee lib cee or lib cee as well. Honestly, I have never heard any different.

Since the pronunciation of “gif” became an issue, I stopped caring about how anyone says anything. My pet giraffe has his own opinion though.

And glibc.

That part of the app is still in development. While it was released last year (on a pre-order model) we don’t anticipate a complete fix until the expansion is out next year.

I didn’t know that. Chloroform always helped my girlfriends melt into my arms, but I never thought about its use on PLA. (Huge /s for people who think I was serious.)

While I was googling around about chloroform smoothing, I also stumbled upon ethyl acetate as a smoother for PLA. It’s probably better for your internet search history to go that route instead. I have a ton of weird shit for my engineering fascinations, but a bottle of chloroform would probably be at the top of that list.

If it’s etched, it’s chemical damage. Just from my 3D printing alone, I know that common chemicals (generally acetone or various alcohols) can easily damage and melt some kinds of plastics. So, I agree. I think we found part of the puzzle.

And you are welcome! Thanks for letting me spew out theories.

It could be a couple of things that I am aware of.

Dust would be the most obvious. Many plastics can hold a static charge and dust can stick to it. The pattern looks “splotchy”, so if not static electricity, it might be oils or some other kind of chemical that is mildly sticky. (Injection molding can sometimes use release agents during manufacturing that are rarely cleaned off. Don’t eat random bits of injection molded plastic, kids.)

Simple moisture could be the issue as well. If you have been using your air conditioning, it’ll get the plastic cold and water can condense on it. Dust or something else might be sticking to it. The water could dry, leaving behind the dust and obfuscating the root cause.

While it could be a mold of some kind, it doesn’t look too much like it. That would point to existing mold in the ducts that is sporulating. Those kinds of house molds are usually dark and nasty, not white. White house molds exist but I suspect it’s region specific as to what kind would grow where you are at. (I grow mushrooms, so I have a supply of petri dishes I would test that substance on, TBH.)

Just for good measure, check your air filters. It’s something you need to do anyway and if they are nasty or old, you could be circulating excess dust in your house and it’s a sign the filters need to be changed. Air filters are functional! Air conditioner heat exchangers can get clogged and, depending on the type of unit you have, be somewhat costly ($500-$1500) to clean properly. I have paid for this procedure twice before I found out that the air filter assembly is garbage in my unit.

Is the substance oily or powdery? If you clean it off, how long does it take to come back? Did someone spill something near that register that you weren’t aware of? Were the carpets recently cleaned?

I am sure that HVAC people may have a more direct answer, but that is my list of things to check.

It’s the splotchy pattern that is bugging me though. It’s highly unlikely that something is getting sprayed out of the air ducts, other than small quantities of water condensation.

What if history only shows the last 10-15 entries? You might have to actually type the location of the history file or find out if history has any command line switches. (Does it have any switches? Dunno.)

Edit: I think CIS Benchmarks recommended limiting bash history. Regardless, I have seen some installations that only show an abbreviated bash history by default.