I am experiencing issues with the Pi, when I try to work on the Pi trough SSH I suddenly get lageness. At the beginning it works fine, but intermittently the auto-complete or commands on the history take a long time to load and that affects the typing.
How can I find out what is doing this?
Reading around I found that could be an issue with network, the SD card R/W speeds or even the SSH configuration itself, nothing that I tried of what I found around worked for me which was quite disappointing.
I don't know which the problem was exactly on my case.
I found a solution for me thanks to that several time my SSH session dropped an this is particularly painful If on the middle of running a command, so i decided to look for a way to keep session alive independently I found tmux. Which no only allowed me to keep session alive but it improved my ssh response, I read that mosh would do the same but I decided to go with tmux which work perfectly for me.
Related
I picked up an AUPS-A10-R11 DC UPS, and am working with their API to build some monitoring software for my xen host. Their API runs over the USB connection on the device, which presents itself as /dev/ttyUSB# on the host.
I've got things working fine except for one thing that's puzzling me. When I first power on or reboot the host it's connected to, I can't communicate with the device. However, if I open up a screen connection to it:
screen /dev/ttyUSB0 9600
and then close it (ctrl+a, k) then it will work perfectly fine until the next time that you reboot the host.
Does anyone have any idea as to why I would have to connect to the device over screen first? I've pasted my code here: http://susepaste.org/0b8bb37f . When connecting on a fresh reboot, it stops at the "Read Nothing" section of the if...else clause. After connecting to the device with screen, it works fine.
Any thoughts??
Does anyone have any idea as to why I would have to connect to the device over screen first?
Such behavior is almost always related to incomplete termios initialization by your program.
The ideal program would configure a serial terminal for its purposes, and on exit restore the termios configuration back to the way it found it.
But most programs, including terminal emulation programs such as minicom and apparently screen, simply leave their termios configuration instead of restoring it.
Fortunately for you, this leftover termios configuration fills in the missing pieces that allows your program to access the serial terminal as expected.
Review of "your" code suggests that it was copied from the accepted answer of this question. Based on the number of up-votes, this code apparently works for a lot of people. However the author admits it was written before POSIX standards, and therefore the code should not be considered portable. In other words, your mileage may vary.
Apparently you overlooked the alternative answer which is POSIX compliant. A tested termios configuration for blocking non-canonical mode is in that program.
If you prefer to simplify with the use of the cfmakeraw() macro, then here's another code example.
Whew...ok, been wrestling with this for a while and I can't figure out what is going on.
I am new to Azure caching, but at this point I have read a good bit and I think I have it setup right, but something is obviously wrong so what do I know?
Ok, so first I setup a dedicated caching web worker role using this fine tutorial: http://berniecook.wordpress.com/2013/01/27/distributed-caching-in-azure-cache-worker-role/
I have an ASP.net MVC 4 website that is supposed to be using it.
I have my solution set to multiple starting projects with my cloud caching project set to start first, but no matter what I do, I get the "role discovery data is unavailable".
Sometimes in my output log I get that the Role Environment failed to initialize, but not very often. Most of the time the output log says that is succeeds. Regardless of that, I still get the error above.
I was thinking that maybe the issue was because I was running on local azure storage and compute emulators, so I reconfigured and published the Cloud Service to Azure to see if that helped.
It didn't...
The fun part is that there have been exactly 2 times when it suddenly worked (both when I was working locally). 2 times about of about 100. I didn't do anything different...just ran the debugger and poof, it all worked. This at least lends a bit of credit that it is actually setup correctly.
Needless to say, this is putting a huge damper on my productivity so any advice would be appreciated.
Update
Ok, I have figured out a workaround of sorts...I have learned that the reason that it consistently failed was because the development web server was holding onto a file which prevented the caching server to launch correctly.
The workaround is to stop the web server each and every time I want to recompile and run the code. This is obviously not ideal, so any ways to make this more reliable would be appreciated.
Thanks,
David
I don't know if this helps but I find that if I don't shut down the both the storage and compute emulator, I get weird errors, so after doing an F5 and closing the browser down, I manually shut down both emulators
I own a RaspberryPi that I can connect only through ssh. A few days ago it was unsafely powered off. Now when I turn it on I cannot access it. It looks like it turns on but can't get an ip or so.
It is ptovided by fixed IP from router, and when I try to ping this IP, it tells me that the destination host is unreachable.
Is there a way to find out what has happened or the only way is to complete reinstall the OS?
One possibility is that the systems rootfs has been corrupted, this happened to me once with unsafe powerdown on a raspi.
If you have another sd-card, the easiest would be to install a fresh image on it and check if it boots correctly. If not, make an image of your current sd-card, format and reinstall.
Hopefully you've got backups, as there's no guarantee to recover your files if the data has been corrupted.
I've set up raspbian "wheezy" (more information here, and image file here) on my recently arrived raspberry-pi (model B, but with 256MB RAM). Since I plan to use it via SSH from other locations, I was looking for a way to lock the console on the actual machine.
Raspbian is the first unix based OS I am working with, so I'm not really familiar with it, but I think I am looking for something like "vlock".
I installed vlock like this:
apt-get install vlock
When I now log into my pi via SSH from my Windows PC vlock works just fine, but when I try using it on the machine itself it shows a strange behaviour.
If I enter a wrong password, I get the usual message:
vlock: Authentication failure
but immediately after that the commandline shows up as if I entered the right one. So basically everyone can just roll his or her head over my keyboard to unlock my pi.
Does anyone know if this is a known bug (or even intended)? Or are there any equivalents to vlock that I could try?
Thanks in advance.
PS: This is my first question on stackoverflow so I hope I provided enough information. If I didn't, feel free to comment/ask.
This is been making my programming really frustrating lately.
I´m in Argentina right now connecting to a U.S. server via SSH. Understandably, the pings are a bit higher here (around 200ms on average) so when I SSH into the server there is a slightly noticeable lag between each keystroke. This is fine and easy enough to work with.
What isn´t easy to work with is that about every 5 minutes or so, SSH will completely hang and take about 3-5 minutes to return back a prompt. I know the server is not bogged down because I can easily open several new connections while I´m waiting for one to return (in fact this is the only way I´ve been able to work). And when SSH finally comes back I can see it has actually been working away in the background (large file downloads was a good way to test this) but it just hasn´t been updating my screen.
Does anyone have an idea what might be causing this?
Few other facts: the server is Ubuntu and I'm connecting with Mac OS X. I have keepalive turned on in the SSH settings. It is most likely to hang when I hold down a key (for example a left or right arrow to scroll) which sends a lot of keys quickly. In fact I can reliably reproduce the hang by logging in and holding down any key like "a" - it never makes it past a full line of "a"'s before hanging. This just started when I connected internationally for the first time so I´m assuming it has something to do with that (latency?) but can´t say for sure.
Odd. I can't help you with your problem but I have a tip to make it less annoying: Use screen(1). This will keep your shell on the other end alive and you can continue whatever you were doing after reconnecting.
If you only need to run a command on the other side, I suggest to pass the command as an option to ssh (it will connect, run the command, display the result and disconnect).
I think it was some problem with the ISP down here in argentina. When I switched to another wireless network with another ISP it started working. They are probably playing some port throttling games or who knows what.
Try adjusting your TCP window size.
I'm used to ssh over high latency links - 600ms. It is slow but I rarely had any problems. To start with - open another terminal window, ping your server and watch the connection. Tell us what you see.
Try sshing in with a few verbose flags (ssh -vv[vv] somehost) and seeing if there's anything indicative printed around the time it hangs.
Well, I am now connected to a different wireless network and the problem seems to have disappeared. I can't say for sure what exactly was causing it (and I don't have login access to the wireless router) but this seems to suggest it was something on the router, and not the server or client computer.
Both the old router and the new router were Linksys WRT54G's so I'm not sure what the problem was. Hope it helps someone!
I was having a similar problem with 'cat' and even 'ls -l' causing ssh to hang (on Ubuntu). Adjusting MTU size to 1400 fixed it for me.