Arch Linux

ccc1

Member

Registered: 2009-04-16

Posts: 111

[Solved] Safely unmount external usb drive

Hi,

after i umount my external drive, there is still data read/written (?) to the drive for a few seconds, even though the drive doesn't show up as mounted anymore. I guess it has to do with the drive caches.
Is there any command to check if it's safe to remove the drive? I would need it for an undocking scripts ...

ccc1

Last edited by ccc1 (2012-06-13 10:05:35)

karol

Archivist

Registered: 2009-05-06

Posts: 25,440

Re: [Solved] Safely unmount external usb drive

Try https://bbs.archlinux.org/viewtopic.php?id=141392

ccc1

Member

Registered: 2009-04-16

Posts: 111

Re: [Solved] Safely unmount external usb drive

Try https://bbs.archlinux.org/viewtopic.php?id=141392

I think that's a different problem. In my case the umount command exited, "mount" doesn't show the partition as mounted anymore, but it looks like there is still disk activity (led flashes).

ccc1

2ManyDogs

Forum Fellow

Registered: 2012-01-15

Posts: 4,645

Re: [Solved] Safely unmount external usb drive

sync, then unmount, then it's safe.

Last edited by 2ManyDogs (2012-06-12 16:15:36)

skanky

Member

From: WAIS

Registered: 2009-10-23

Posts: 1,847

Re: [Solved] Safely unmount external usb drive

Could try this utility, or check the links in the thread: https://bbs.archlinux.org/viewtopic.php?id=130697

---

"...one cannot be angry when one looks at a penguin."  - John Ruskin
"Life in general is a bit shit, and so too is the internet. And that's all there is." - scepticisle

jdarnold

Member

From: Medford MA USA

Registered: 2009-12-15

Posts: 485

Website

Re: [Solved] Safely unmount external usb drive

Most file explorers on Linux have some kind of option to safely "eject" a USB drive. Which desktop are you using?

rdm

Member

From: Italy

Registered: 2012-05-31

Posts: 48

Re: [Solved] Safely unmount external usb drive

Maybe you'd want to use fuser:

http://en.wikipedia.org/wiki/Fuser_(Unix)

ccc1

Member

Registered: 2009-04-16

Posts: 111

Re: [Solved] Safely unmount external usb drive

sync, then unmount, then it's safe.

That's the best solution. No idea, why i haven't thought of that ...

ccc1

ninian

Member

From: United Kingdom

Registered: 2008-02-24

Posts: 726

Website

Re: [Solved] Safely unmount external usb drive

There's a good discussion and script available at: http://elliotli.blogspot.co.uk/2009/01/ … linux.html
For an up to date Arch though, you've got to tweak the script towards the bottom a bit (name change or something); am not on my Linux system at the moment so can't remember the minor changes exactly. Let me know if you want the tweaked script and I can post it somewhere later.

Last edited by ninian (2012-06-13 10:25:21)

skanky

Member

From: WAIS

Registered: 2009-10-23

Posts: 1,847

Re: [Solved] Safely unmount external usb drive

There's a good discussion and script available at: http://elliotli.blogspot.co.uk/2009/01/ … linux.html
For an up to date Arch though, you've got to tweak the script towards the bottom a bit (name change or something); am not on my Linux system at the moment so can't remember the minor changes exactly. Let me know if you want the tweaked script and I can post it somewhere later.

That's linked from the blogpost linked at the OP of the thread I posted to. I only mention it as the forked pmount that is the point of that thread is based on the script.

---

"...one cannot be angry when one looks at a penguin."  - John Ruskin
"Life in general is a bit shit, and so too is the internet. And that's all there is." - scepticisle

ninian

Member

From: United Kingdom

Registered: 2008-02-24

Posts: 726

Website

Re: [Solved] Safely unmount external usb drive

That's linked from the blogpost linked at the OP of the thread I posted to. I only mention it as the forked pmount that is the point of that thread is based on the script.

Ah, yes. I tried the safe-removal pmount a while back and had some problems with it IIRC. So that's why I went back to the original script, and I'm now using it (modified as I mentioned) in conjunction with a script calling udevil to unmount.

skanky

Member

From: WAIS

Registered: 2009-10-23

Posts: 1,847

Re: [Solved] Safely unmount external usb drive

That's linked from the blogpost linked at the OP of the thread I posted to. I only mention it as the forked pmount that is the point of that thread is based on the script.

Ah, yes. I tried the safe-removal pmount a while back and had some problems with it IIRC. So that's why I went back to the original script, and I'm now using it (modified as I mentioned) in conjunction with a script calling udevil to unmount.

Okay, let us know the script change.

---

"...one cannot be angry when one looks at a penguin."  - John Ruskin
"Life in general is a bit shit, and so too is the internet. And that's all there is." - scepticisle

ninian

Member

From: United Kingdom

Registered: 2008-02-24

Posts: 726

Website

Re: [Solved] Safely unmount external usb drive

Okay, let us know the script change.

Here's the patch for you (not a lot to do):

--- suspend-usb-device	2012-06-13 20:21:08.311449540 +0100
+++ suspend-usb-device.patched	2012-06-13 20:24:53.702254506 +0100
@@ -160,7 +160,7 @@
 
     # check if CONFIG_USB_SUSPEND is enabled
     [[ $VERBOSE == 1 ]] && echo "Checking whether $DEVICE can be suspended"
-    POWER_LEVEL_FILE=/sys${DEVICE}/power/level
+    POWER_LEVEL_FILE=/sys${DEVICE}/power/control
     if [ ! -f "$POWER_LEVEL_FILE" ]; then
         1>&2 cat<<EOF
 It's safe to remove the USB device now but better can be done. The
@@ -177,5 +177,5 @@
     fi
 
     [[ $VERBOSE == 1 ]] && echo "Suspending $DEVICE by writing to $POWER_LEVEL_FILE"
-    echo 'suspend' > "$POWER_LEVEL_FILE"
+    echo 'auto' > "$POWER_LEVEL_FILE"
 fi

skanky

Member

From: WAIS

Registered: 2009-10-23

Posts: 1,847

Re: [Solved] Safely unmount external usb drive

Okay, let us know the script change.

Here's the patch for you (not a lot to do):

--- suspend-usb-device	2012-06-13 20:21:08.311449540 +0100
+++ suspend-usb-device.patched	2012-06-13 20:24:53.702254506 +0100
@@ -160,7 +160,7 @@
 
     # check if CONFIG_USB_SUSPEND is enabled
     [[ $VERBOSE == 1 ]] && echo "Checking whether $DEVICE can be suspended"
-    POWER_LEVEL_FILE=/sys${DEVICE}/power/level
+    POWER_LEVEL_FILE=/sys${DEVICE}/power/control
     if [ ! -f "$POWER_LEVEL_FILE" ]; then
         1>&2 cat<<EOF
 It's safe to remove the USB device now but better can be done. The
@@ -177,5 +177,5 @@
     fi
 
     [[ $VERBOSE == 1 ]] && echo "Suspending $DEVICE by writing to $POWER_LEVEL_FILE"
-    echo 'suspend' > "$POWER_LEVEL_FILE"
+    echo 'auto' > "$POWER_LEVEL_FILE"
 fi

Thanks

---

"...one cannot be angry when one looks at a penguin."  - John Ruskin
"Life in general is a bit shit, and so too is the internet. And that's all there is." - scepticisle