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125

Ctrl-Q To disable this altogether, stick stty -ixon in a startup script. To allow any key to get things flowing again, use stty ixany. ps: It's neither the terminal nor the shell that does this, but the OS's terminal driver.


90

Ctrl-Q is indeed the answer. I thought I'd toss in a little history of this that is too long to fit in the margins of ak2's correct answer. Back in the dark ages, a terminal was a large piece of equipment that connected to a remote device (originally another terminal because teletypes were so much easier to learn to operate than a telegraph key) over a long ...


16

Are you using a 64-bit version of Linux with a lot of memory? In that case the problem could be that Linux can locks for minutes on big writes on slow devices like for example SD cards or USB sticks. It's a known bug that should be fixed in newer kernels. See http://lwn.net/Articles/572911/ Workaround: as root issue: echo $((16*1024*1024)) > ...


11

A better solution than turning off swap, which will at best cause random processes to be killed when memory runs low, is to set the per process data segment limit for processes that pull stuff off the net. This way a runaway browser will hit the limit and die, rather than cause the whole system to become unusable. Example, from the shell (ulimit -d ...


10

The pipe symbol is sending the ouput of nano to the input of the uniq command. However, nano is still running and receiving your keyboard input. It's just that you can't see its ouput as uniq won't ouput it's results until it sees an End-Of-File (this isn't important to the question). When you press ctrl-c it is 'caught' by nano, but it does not cause it ...


8

If the screen and input devices (keyboard and mouse or trackpad) froze, the first place to start by looking would be in /var/log/Xorg.0.log (assuming that Xorg is running on the first display server). If that doesn't yield any immediate clues, the next logs to check would be /var/log/messages.log and /var/log/dmesg.log. If you are unable to find anything ...


8

Disabling swap won't do what you want. You will still get violent I/O throughput, but it will be of clean pages rather than dirty ones. With no swap, the system will compress the cache of clean (unmodified) pages to near zero, because those are the only pages it can evict from physical memory. It can only evict dirty (modified) pages from memory by writing ...


5

If you have a keyboard attached, you could do the RESUIB method. Otherwise try to ssh into your box, and us top, ps and the usual helper and log checker programs to hunt down your problem.


5

To make this change pervasive you'll need to add these limits to the entire environment. Changes using the ulimit command are only to the current environment. NOTE: This will have no effect on the root user! Example Edit this file: vi /etc/security/limits.conf and add entries to the file limiting the number of processes (nproc) that a specific user or ...


5

The superuser or any process with the CAP_SYS_ADMIN or CAP_SYS_RESOURCE capabilities are not affected by that limitation, that's not something that can be changed. root can always fork processes. If some software is not trusted, it should not run as root anyway.


5

They are probably very related. STOP USING THAT COMPUTER UNTIL YOU FIX THE FAN It can only take milliseconds for the CPU to go from "OK" to "OMG I melted". They should never be used with out proper cooling. To do so, will cause damage, and could cause a fire, injury, and all manor of bad things. That warning aside Linux and most semi-modern computers ...


4

If you want a way to reboot, without saving open documents, but without hitting the reset button, then there are ways that are less likely to cause data loss. First, try Ctrl+Alt+F1. That should bring you to a virtual console, as ixtmixilix said. Once you're in a virtual console, Ctrl+Alt+Delete will shut down and reboot the machine. If that technique ...


3

Disable all your browser plugins, and add-ons, and extensions. Then surf the web for a while. Try to note which site is open when your computer freezes. See if your can reliably replicate the issue. Gradually enable your plugins and addons. Note which one is enabled last before the system starts freezing again. My money's on Flash or Java.


3

Not exactly what I was looking for but close: iotop -o So I will use: sudo nice -20 sudo iotop -tbod10 > ~/iotop.log


3

There are the so-called "Magic SysRq keys" -- a set of keypresses that can be embedded at kernel level and will be honored as long as both the kernel process and the keyboard interrupt are still being listened to, and can be called by alt-SysRq-keypress. These can perform various emergency tasks such as an emergency S ync of all mounted filesystems, k I ...


3

It sounds like your kernel panicked in some way such that sshd couldn't send the server keys. Possibly, the kernel was wedged in such a way that the network stack was still up, but the vfs layer was unavailable. When I experienced similar problems on a RHEL4 system, I set up the netdump and netconsole services, and a dedicated netdump and syslog server to ...


3

Yes , the easiest way to archieve this , is enable the keys to kill Xorg server , and re-launch X session. To enable this , open System Settings -> Keyboard Layout options (or use keyboard command in Unity interface , hit ALT + F2) , and check this option: Control + Alt + Backspace So when it hangs , hit CTRL + ALT + Backspace will kill X server , and ...


3

Try removing any extra plugins or syntax files you have for editing JS files. A poorly written vimscript or syntax file (basically a bunch of regexes) can make Vim eat all CPU cycles in a blink.


3

This is a bug in Fedora 17. You can work around it by disabling the Plymouth boot screen: systemctl mask plymouth-start.service It will be fixed in Fedora 18.


3

You are presumably using the i915 driver for the integrated video, and I bet it has something to do with this bug: https://bugzilla.kernel.org/show_bug.cgi?id=58381 Since the "freezing" is a kernel panic. Try: grep i915_hangcheck_hung /var/log/* And see what turns up. You might try turning off "use hardware acceleration when available" in chrome ...


3

I don't know what the Cinnamon guys renamed gnome-shell when they forked, so you'll have to find this out. It's probably either cinnamon-shell or cinnamon or something. I'll assume it's called cinnamon. Now, the GNOME Shell - and by extension, Cinnamon - will respond to SIGHUP by completely reinitializing. It's basically the same as typing r into the AltF2 ...


3

For some weird reason, cpio doesn't like to take a file argument. Instead, you have to pipe the archive into cpio. An inexperienced user would do the following: cat initramfs-linux.img | cpio -i However, this would get you the Useless Use of cat Award. A better way would be: cpio -i < initramfs-linux.img This uses the shell's built-in redirection ...


2

To me this sounds like the system is out of resources so the process needed by the server side of ssh cannot be allocated. The actual bottleneck can vary - out of processes or out of memory - and the only way to be sure is to look at the logs and console to see if anything is present there. You may want to set up a scenario of pre-started ssh-jobs - one to ...


2

I will bet dollars to donuts that you are running out of memory. The system is grinding to a halt as it tries to figure out where to get some from. It may be happening so quickly that your monitoring doesn't catch it. I'd step up monitoring, including remote logging of memory usage. Check in the logs for OOM messages as well. (You may even just want to have ...


2

If the problem is related to the x session (which, many are) you should be able to ctrl-alt-f1, ctrl-alt-f2, ... to get to a virtual session. from there you can top, as suggested above, or, all else fails you can sudo reboot to (as cleanly as possible) get running again.


2

To make sure that swap is not used, you'd be better off preventing any swap being added at boot. This can be done, depending on the system, by disabling the swap boot service or just commenting out the swap entry in /etc/fstab. As far as your hangup is concerned, the stop() function in /etc/init.d/swap might give a clue: stop() { ebegin ...


2

Maverick was particularly prone to graphics freezes with the standard Open-Source nouveau drivers. You can uplift you X-System using the X-Updates PPA sudo add-apt-repository ppa:ubuntu-x-swat/x-updates sudo apt-get update && sudo apt-get upgrade You can then install the latest NVIDIA drivers. As you have noted, the Open-Source drivers still ...


2

Removing a file or directory is an atomic operation requiring one system call, so if the rm command hangs, it's because the kernel is stuck. On an NFS filesystem, this can be (and usually is) due to the server not responding. On a local filesystem, this can be (and usually is) due to a hardware failure. Your disk is probably failing; the kernel logs would ...


2

The natural state of things is that application data is in RAM, and files are on disk. The ideal state of things, performance wise, is that data in frequent use is in RAM, and data that isn't needed at the moment is on disk. On a normal system, the kernel does two things to attempt to reach this ideal: Application data that has not been used for a while ...


2

The kernel probably did log some information, but they never made it on time to the disk. If your laptop has got a serial port, set the kernel to use it as console (add console=ttyS[X] as boot option); you will see the messages there from another machine as it happens. If not, you can use an Ethernet port and try netconsole. In general, you have a problem ...



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