I have a new-ish Nexus 4 with Cataclysm ROM installed (rooted, 4.3).

The device has recently started freezing - being unresponsive to button presses, but with the white LED pulsing. I have to long-press the power button and then press it again to restart.

It used to freeze occasionally - say, once a week - but over the past week or two it has started to freeze every day or at least every other day.

I cannot think of a recently-installed application or setting change that might have triggered this.

I'm wondering if there's a way for me to determine 'when' the device freezes and 'what' it is that's causing it to freeze, ideally so I can determine whether or not it is the ROM or the device at fault. Is there an application that can log device behaviour and be read by a semi-technical user like me?

  • 2
    You may want to look into using adb logcat. Google has a documentation page for it over here. There's also a question on our site called How can I view and examine the Android log? that you may want to check.
    – dotVezz
    Jan 9, 2014 at 14:34
  • Probably the best way to determine if the rom is at fault is to jump back to stock rom and run that for a while, if you're still experiencing issues, then it's almost positively a hardware issue. Logcat is a good solution after you've determined it's not a hardware issue, so you can post back the information to the rom developer(s) and it can be correctly debugged. Jan 9, 2014 at 20:12
  • I might get murdered for this one, but CyangoenMod has been quite buggy and laggy for me on my HTC One, Nexus 4, HTC Desire, Galaxy S4 to various degrees. I've moved from it to an ASOP / Wanam Xposed combination so I have a stable OS with all the customisation I want. I'm not knocking CyanogenMod they're a great group but I would definitely try another ROM first as the others suggested.
    – RossC
    Jan 10, 2014 at 12:50

1 Answer 1


There are some ways to pin down your problem. The easiest way should be reading out the last_kmsg which is normally stored under /proc/last_kmsg. The kernel logs everything in there and it can be read until the next reboot.

So reading last_kmsg always shows things that happened before the device rebooted the last time.

Another way would be using "adb logcat" or - more comfortable - the app Catlog which can record your logcat into a .txt file on the SD-Card. Be advised that logcat is not the same as a kernel message but it also includes messages from user space apps and UI stuff.

If I'm allowed to make a wild guess, I'd say that it's the ROM's fault (e.g. undervolting or something else going wrong).

Best regards!

  • I'm hoping it's the ROM and not the phone. I'll try the methods you mention next time the phone freezes.
    – James
    Jan 24, 2014 at 8:36
  • Just tried reading last_kmsg and it wouldn't open with a text editor. Tried sending to Dropbox and it wouldn't. It wouldn't even copy to another location on the device.
    – James
    Jan 25, 2014 at 16:28
  • Looks like you don't have the right to read it. Are you trying to read it as root? What are the file properties? It should be -r--r-----.
    – visi0nary
    Jan 27, 2014 at 9:34

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