Re: sustained write to disk, frozen copy

[Zheng Liu <gnehzuil.liu@gmail.com>]

On Sat, Apr 27, 2013 at 08:16:02AM +0100, LuVar wrote:
> Hi,
> I have my desktop about 24 hours in "deadlock". I was copying (as root in krusader from USB key (mounted as [1]) data to filesystem [2]) some files from one point to another. Now it is more than 24 hours with sustained disk write, see [3].
> 
> How can I help and "debug" this problem? I have 3.5.7 gentoo kernel ([4]).

Hi LuVar,

You could use 'echo w >/proc/sysrq-trigger' to look at which process has
been deadlock.

 # echo w >/proc/sysrq-trigger (WARN: you need a root privilege)
 # dmesg | vim -

 SysRq : Show Blocked State
   task                        PC stack   pid father

Here is nothing because my system hasn't any deadlock.  Then you could
use 'echo t >/proc/sysrq-trigger' to dump current tasks and their
information.  That would be great if you could paste these details in
mailing list.  They are very useful for us to dig this problem.

Thanks,
                                                - Zheng

> 
> PS: I am an average user, so please by verbose to me.
> 
> [1] sudo mount -o rw,uid=luvar,gid=luvar,iocharset=utf8 /dev/sdg1 /mnt/usbstick/
> 
> [2]:
> luvar@blacktroja ~ $ mount | grep music
> /dev/mapper/vg-music on /var/lib/mpd/music/local type ext4 (rw,noatime,commit=0)
> 
> [3]:
> iotop, two first records :
> 17714 be/3 root        0.00 B/s    0.00 B/s  0.00 % 97.60 % [jbd2/dm-3-8]
>  6546 be/4 root        0.00 B/s    0.00 B/s  0.00 % 93.48 % kdeinit4: kio_file [kdeinit] file local:/tmp/ksocket-root/~-socket local:/tmp/ksocket-root/krusaderZz6431.slave-socket
> 
> [4]:
> luvar@blacktroja ~ $ uname -a
> Linux blacktroja 3.5.7-gentoo #1 SMP Sun Oct 28 17:18:07 CET 2012 x86_64 Intel(R) Core(TM) i7 CPU 930 @ 2.80GHz GenuineIntel GNU/Linux
> 
> Thanks, LuVar
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