process really strange.

bruse · 10-13-2005, 03:57 AM

look at my process.

[root@localhost root]# ps -aux | grep dd
Warning: bad syntax, perhaps a bogus '-'? See http://procps.sf.net/faq.html
root 2835 0.0 0.2 1824 516 pts0 D 14:05 0:00 dd conv noerror if /dev/hdc of /root/mandrake_cd1.iso
root 2925 0.0 0.2 1936 632 pts4 R 14:13 0:00 grep dd
[root@localhost root]# kill -SIGKILL 2835
[root@localhost root]# kill -SIGKILL 2835
[root@localhost root]# kill -SIGKILL 2835
[root@localhost root]# kill -SIGKILL 2835
[root@localhost root]# kill -SIGKILL 2835
[root@localhost root]# kill -9 2835
[root@localhost root]# kill -9 2835
[root@localhost root]# kill -9 2835
[root@localhost root]# kill -9 2835
[root@localhost root]# kill -9 2835
[root@localhost root]# kill -9 2835
[root@localhost root]# kill -9 2835
[root@localhost root]# kill -9 2835
[root@localhost root]#
This process takes a high number of strokes to kill???
why does this much kill signal??
can u figure this out?

zhangmaike · 10-13-2005, 04:27 AM

This process was probably writing to the disk at the time you tried to kill it - the key here is the D flag from ps:

A quote from the man page:

Quote:

PROCESS STATE CODES
Here are the different values that the s, stat and state output specifiers
(header "STAT" or "S") will display to describe the state of a process.
D Uninterruptible sleep (usually IO)
R Running or runnable (on run queue)
S Interruptible sleep (waiting for an event to complete)
T Stopped, either by a job control signal or because it is being traced.
W paging (not valid since the 2.6.xx kernel)
X dead (should never be seen)
Z Defunct ("zombie") process, terminated but not reaped by its parent.

As you can see, the D stands for an uninterruptible sleep, in this case probably caused by IO.

The repeated signal sending probably didn't help at all, it just took a long time for the uninterruptible sleep to end and the first signal to be received.

So, see the man page for ps for more details.

bruse · 10-13-2005, 04:56 AM

yeah i understand thanks.
is there any way to suddenly kill this kind of "D Uninterruptible sleep (usually IO"?

zhangmaike · 10-13-2005, 10:57 AM

Nope - it's uninterruptible.

bruse · 01-22-2006, 10:17 PM

I always logged in to this kind of process hanging problem.So it continuously running.There should be a key u know to off the process even if the process is uninterruptible.

subratabera · 01-26-2006, 09:33 AM

I am also facing a same kind of problem. I have a pppd process with "Ds -- Disk Sleep" process status. Its parent is init. Is there any way to kill this process without restarting my computer. Please help...

btmiller · 01-26-2006, 07:13 PM

If it's in D state it's completely unkillable. It may be accessing disk DMA buffers or other hardware dependent resources. Sudden termination might cause thise buffers to become corrupted. if you frequently get processes stuck in the D state reading to/from the disk you should look into the possibility that your disk is going bad, as this should not happen.

magic_ghost · 01-27-2006, 06:23 AM

Could you not just stop it from running at startup?

subratabera · 01-30-2006, 02:20 AM

No. This is pppd process which is stucking whenever I try to connect to the Internet. I can't avoid running this process. But whenever it get stuck, I have to reboot my PC to connect to Internet again. Is there a way to maually kill the pppd process with "Disk Sleep" status or is there a way to run the pppd process within another process (I mean shell), so that I can kill the shell to kill the stucked pppd process. Please help & sorry for my poor English...

BenJoBoy · 01-30-2006, 03:34 AM

hmmm, try ifdown first on the interface pppd is using to connect. or try some other pppoe deamon.

timmeke · 01-30-2006, 04:15 AM

To explain a little what the "uninterruptability" means.
Basically, the process is calling your system (kernel) to perform some action, typically related to IO (ie reading from/writing to disk, accessing a certain device like a modem, etc).
When the kernel is trying to perform the system call (ie actually handle the IO request), it sometimes needs to be uninterruptable. As posted already, a nice example would be when an interrupt of the kernel's routine would mess up your hardware (buffers, etc).

The bottomline is that you shouldn't interrupt this process at all. That's why they are made "uninterruptible".
If programs stay in this state a long time, then there's most likely a problem with using/accessing your hardware. For instance, your disk controller can be unresponsive (ie if the disk is going bad or was mounted the wrong way). Or your modem doesn't respond to the kernel's requests.
So, you should try looking at your system logs to see what exactly is going wrong and try to fix that. Killing an uninterruptible process isn't desirable and also impossible (except by a reboot).

subratabera · 01-31-2006, 01:09 PM

Thankyou BenJoBoy & timmeke for your kind replies.
I am using kubuntu Linux 5.10. BenJoBoy can you please explain what are other ppp daemons are available in kubuntu Linux and also how to use them (especially ifdown & pppoe deamon).

timmeke · 02-01-2006, 01:46 AM

"ifdown" isn't a daemon. It's just a program you can use to check if a network interface is "down" (ie not up and running). "ifup" is it's counterpart.

subratabera · 02-02-2006, 11:52 AM

Thanks for your reply timmeke.

Subrata Bera.