Scientific Linux 6.3 hangs on suspend if using a samba share

Question

I have several notebooks running Scientific Linux 6.3.

The suspend function is working quite well, except for one problem:

When a notebook mounts a Samba share, plays a few videos through this share then the suspend function stops working, and the notebook suddenly needs 5 minutes to suspend.

Again, this problem only occurs if they watched videos over the samba share.

QUESTION: WHY? does samba keeps something open and need a timeout of 5 minutes, just after the suspend function has been involved or what?

Any suggestions on where to look to find out what's going on would be appreciated. Or a way for I could write a bash script to check when is the suspend button pressed so that I could do xy* thing to the machine.

(*xy=anything that corrects this problem)

Answer 1

I made the experience that samba shares react pretty bad if the connection gets interrupted while they're mounted.

Possibly the network is going down before the storage, so it may be that your system is trying to do anything with the samba share which is not possible without network connection. A workaround would be to auto-unmount it on suspend (and maybe remount it afterwards):

#!/bin/bash
if [ $1 == "suspend" ]; then
    umount -afl -t cifs
fi

If you place that in /etc/pm/sleep.d/ and make it executable, it should execute upon every suspend. I cannot really test though if it happens soon enough, just give feedback in the comments. However, you'll have problems if programs are still accessing the files in the share. -l should still unmount it from the filesystem tree, -f will make sure it works when the share server is not reachable.

You could extend that to be stateful and (attempt to) restore your mounts on resume.

I was unable to find official sources. The best is possibly to check out the linux kernel source and see in which order devices are sent to suspend and look what cifs tries to do upon suspend and so on.

Answer 2

1)

configure sudo permissions:

visudo
USERNAME ALL = NOPASSWD: /bin/mount //192.168.1.1/Share /home/USERNAME/Desktop/Share -t cifs*
USERNAME ALL = NOPASSWD: /bin/umount -f -a -t cifs
USERNAME ALL = NOPASSWD: /bin/umount -f -l -a -t cifs
USERNAME ALL = NOPASSWD: /sbin/modprobe -r -f cifs

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2)

with normal user:

vi ~/.mountsamba.sh; chmod +x ~/.mountsamba.sh
#!/bin/bash
case $1 in

mount)
echo 'In progress...'
/usr/bin/sudo /bin/mount //192.168.1.1/Share /home/USERNAME/Desktop/Share -t cifs -o ro,bg,intr,soft,noexec,nosuid,nodev,password=,nolock
pkill nautilus
echo "MOUNTShare - `date`" | /usr/bin/logger
;;

umount)
echo 'folyamatban...'
/usr/bin/sudo /bin/umount -f -a -t cifs
/usr/bin/sudo /bin/umount -f -l -a -t cifs
sleep 5
/usr/bin/sudo /sbin/modprobe -r -f cifs
pkill nautilus
echo "UMOUNTShare - `date`" | /usr/bin/logger
;;

*)
exit 1
;;

esac

======================================================================
3)

put icon in GNOME-panel:

gnome-terminal -x bash -c "/home/USERNAME/.mountsamba.sh mount"
gnome-terminal -x bash -c "/home/USERNAME/.mountsamba.sh umount"

======================================================================
4)

if you want to use autofs:

vi /etc/auto.master
/-  /etc/auto.samba --timeout=120

vi /etc/auto.samba
/home/USERNAME/Desktop/Share    -fstype=cifs,bg,intr,soft,ro,noexec,nosuid,nodev,password=,nolock   ://192.168.1.1/Share