If you're getting a freeze while you're formatting the disk, since mke2fs is a userspace program and the ext4 kernel code isn't running at all, and you are also sometimes getting a freeze when writing to the file system, the code which is in common in those two cases is the block device layer and the device driver itself. (And perhaps the disk controller hardware, I suppose.)
What would be really useful in debugging this is would be to determine if there is any kind of crash dump before the system freezes. Unfortunately, if you have X running, the crash dump might not be visible, unless you can set up a serial console. Or if you could make sure you are in the VT console while trying to format the disk. At that point, if even if you don't get a crash dump, we can use the magic sysrq key (alt-sysrq if you are using a VT console, or break if you are using a serial console) to get some information about the frozen system. See the Wikipedia article on "magic sysrq key" if you're not familiar with this option. When debugging system freezes, I find that sysrq-p multiple times, to and recording the IP (instruction pointer aka program counter on other systems), to see where the kernel is executing, sysrq-w, to see list of blocked tasks, sysrq-d, to see all currently taken locks, are most helpful. If it looks like the system is swapping its brains out, or is behaving as if it's running into memory problems, sysrq-m is also useful. I doubt this is happening in your case, though. Note that some of these sysrq messages will print a *lot* of information, far more than can be held in a VT screen, or even the VT scrollback buffer. So setting up a serial console is also a good idea. There are a number of resources on the web which will give you instructions on making this work. Note that you need to modify the kernel boot command line to specify the serial console, since what's important for this case is not logging into the system via the serial console (which is what configuring inittab and/or getty will do) but rather petting kernel messages be sent to the serial console (which requires setting up the serial console via the kernel command line at boot time). Hope this helps you gather the information you need.... -- ubuntu 10.04 ext4 fast Ram and Fast hd's freezes at random https://bugs.launchpad.net/bugs/632346 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
