[CentOS] RAID level and killing a job

Tue Jan 13 19:22:30 UTC 2009
Scott R. Ehrlich <scott at MIT.EDU>

On Tue, 13 Jan 2009, William L. Maltby wrote:

> On Tue, 2009-01-13 at 10:04 -0800, nate wrote:
>> <snip>
>>> Second question - A newly installed server consisting of CentOS 5.2,
>>> straight
>>> off the DVD, I invoke a command by hand, realize I want to kill it soon
>>> after
>>> (logged in as root).  I issue ps auwx|grep name_of_command, get the PID, and
>>> issue kill -9 PID.  ps auwx|grep name_of_command is still running.
>>> The command is NOT part of any scheduled job.    Why won't the process die?
>> Is the process state "D" or "Z" ? Frequently either of these states
>> can trigger an unkillable process. Sometimes "Z" (zombies) can be
>> killed but often times they can't be directly killed. And if the
>> process is in "D" then it is stuck waiting for I/O(most often) and
>> you have to wait for it to complete, or reboot, sometimes going to
>> single user mode and back again works as well, and sometimes killing
>> other processes that the stuck one depends on can sometimes free it
>> up so it can die.

I discovered, by chance, the Xen kernel was getting in the way.  I booted 
to the non-Xen kernel and all is well.