killing uninterruptible sleep process
Hi I logged in to one of my servers today and noticed that the load average is very high. After investigating the problem I found two processes in D stat (uninterruptible sleep): root 24344 0.0 0.2 1532 584 ?DN Jul21 0:01 /usr/bin/updatedb -f NFS,SMBFS,NCPFS,PROC,DEVPTS -e /tmp,/var/tmp,/usr/tmp,/afs,/net root 25899 0.0 0.2 1532 584 ?DN 06:26 0:01 /usr/bin/updatedb -f NFS,SMBFS,NCPFS,PROC,DEVPTS -e /tmp,/var/tmp,/usr/tmp,/afs,/net Their parent - pid 1532 is already dead. My guess is that SMB share that I had mounted on this box have died after the host rebooted. I cannot unmount that share because umount says that the device is busy. Is there any way to kill the dead updatedb processes and umount the dead shares without rebooting the system? Sagi = To unsubscribe, send mail to [EMAIL PROTECTED] with the word unsubscribe in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
Re: killing uninterruptible sleep process
On Mon, 22 Jul 2002, Sagi Bashari wrote: I logged in to one of my servers today and noticed that the load average is very high. After investigating the problem I found two processes in D stat (uninterruptible sleep): root 24344 0.0 0.2 1532 584 ?DN Jul21 0:01 /usr/bin/updatedb -f NFS,SMBFS,NCPFS,PROC,DEVPTS -e /tmp,/var/tmp,/usr/tmp,/afs,/net root 25899 0.0 0.2 1532 584 ?DN 06:26 0:01 /usr/bin/updatedb -f NFS,SMBFS,NCPFS,PROC,DEVPTS -e /tmp,/var/tmp,/usr/tmp,/afs,/net Their parent- pid 1532 is already dead. My guess is that SMB share that I had mounted on this box have died after the host rebooted. I cannot unmount that share because umount says that the device is busy. Is there any way to kill the dead updatedb processesand umount the dead shares without rebooting the system? no. that's why its called 'uninterruptible sleep'. 'kill -9' wn't help either, in such cases - they'll go away only when you reboot the mchine (and that reobot could get stuck while trying to umount the file systems, forcing you to reset the machine). this is an annoying problem, indeed. -- guy For world domination - press 1, or dial 0, and please hold, for the creator. -- nob o. dy = To unsubscribe, send mail to [EMAIL PROTECTED] with the word unsubscribe in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
Re: Why do we need uninterruptible sleep? (was: Re: killing uninterruptible sleep process)
On Mon, Jul 22, 2002, Omer Zak wrote about Why do we need uninterruptible sleep? (was: Re: killing uninterruptible sleep process): Why then there is such a thing as uninterruptible sleep in Unix/Linux? What useful purpose (besides full Posix conformance) does this serve? As far as I know, processes are put into uninterruptible sleep (D) state when it is either too complicated, or the programmer was too lazy, to decide what to do in the case that the process would be killed during the sleep. The quintessential case is a process that is waiting for a disk page to be copied to its memory, or for one of its virtual-memory pages to be swapped into core from disk. What would (or should) happen if a process will be killed at this point? When the disk hardware is finally ready to fetch the page, the process is no longer there and its memory pages have gone the way of the dodo. It would be simpler if the process simply could not be killed at this point. However, A good kernel design should only use the D state sparingly, and only for very short term operations that are sure to succeed (such as fetching a page from disk). A bad design, on the other hand, would use it in many places where a process being killed might complicate the programmer's life, such as when waiting for RPC replies (such as in NFS) or the SMB stuff you may have noticed. In my opinion, all these cases which might result in processes being stuck in the D state for a long time, should be considered bugs in the kernel and should be fixed. -- Nadav Har'El| Monday, Jul 22 2002, 13 Av 5762 [EMAIL PROTECTED] |- Phone: +972-53-245868, ICQ 13349191 |Entropy: Not just a fad, it's the future! http://nadav.harel.org.il | = To unsubscribe, send mail to [EMAIL PROTECTED] with the word unsubscribe in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
