udev delays mounting USB devices during heavy I/O

[Rocko]

Binary package hint: udev, nautilus

To reproduce:

1. Insert a (slow) usb key and let nautilus automount it.

2. Start copying a large file to this usb key, eg 700 MB.

3. While the copy is underway, insert another USB key.

nautilus either mounts the second usb key when the file copy finishes, or doesn't mount it at all.

The attached syslog shows the latter event (ie the second USB never gets mounted - it didn't even appear in nautilus's Places sidebar to let me manually mount it). It also shows /bin/sync being blocked, which might be relevant.

This happens in Ubuntu 9.04 and 9.10. I'm using the 2.6.32.2 kernel, but it also happens with the stock 2.6.31 kernel.

ProblemType: Bug
Architecture: amd64
CheckboxSubmission: 1bd8e90541d49b96c13cbfcc9baf103b
CheckboxSystem: d00f84de8a555815fa1c4660280da308
Date: Thu Jan 7 11:19:02 2010
DistroRelease: Ubuntu 9.10
NonfreeKernelModules: nvidia
Package: gnome-volume-manager (not installed)
ProcEnviron:
 PATH=(custom, user)
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-volume-manager
Uname: Linux 2.6.32.2-generic x86_64

[tankdriver (stoneraider-deactivatedaccount)]

gnome-volume-manager is not installed per default (on karmic).
I made an other report: Bug #503345

[Rocko (rockorequin)]

Correct, it isn't installed. I think I read that Karmic uses udev instead of hal for auto-mounting, so perhaps that's why g-v-m isn't installed. I've changed the bug description to udev in case it's more accurate.

[Rocko (rockorequin)]

Some extra info: I reproduced this bug just now and tried mounting the just-inserted external USB key manually with:

sudo mkdir foldername
sudo mount /dev/sdg1 foldername

but the mount command returned the error 'special device /dev/sdg1 does not exist'. The syslog showed that /dev/sdg1 had already been recognised by the system, however.

[tankdriver (stoneraider-deactivatedaccount)]

the /dev/sdx1 messages appear immediately. So I think udev is OK. The next "higher" Step of mounting is devicekit-disk. I think the bug is there. Please take a look at the duplicate Bug. (#503345)

[Scott James Remnant (Canonical) (canonical-scott)]

Please run "sudo udevadm monitor -e" in a terminal, then plug in your USB key. You should see two groups of output, copy and paste this into the bug report. Thanks

[Rocko (rockorequin)]

The output from sudo udevadm -e is attached. I ran udevadm while copying to a slow USB device, and there was the usual delay during mounting - I've marked where it happened in the file (after seqnum 2147).

[tankdriver (stoneraider-deactivatedaccount)]

Similar Test case: I copyed a big (3.8GB) file to an USB-Stick.
During that i started "sudo udevadm -e" and plugged in a 2nd USB-Stick
The copy process took ~8 minutes. The 2nd USB-Stick did not mount. Not during copyprocess and not after.
Log is attached. The first entry in the log is when I plugged in the 2nd USB-Stick.
(1st Stick Manufacturer: Corsair, 2nd: Trek)