Suspend-to-ram does not work in loop-installations

[Agostino Russo]

In loopinstallations such as the ones used by the Windows Installer (https://blueprints.launchpad.net/ubuntu/+spec/installer-for-windows) root is loop mounted on a file within ntfs (in turn mounted via ntfs-3g/fuse).

In such scenario suspend-to-ram fails, Matthew Garrett had a preliminary look at the issue some time ago', my understanding is that the issue is due to the oredering with which processes are stopped/resumed.

[Leann Ogasawara (leannogasawara)]

Hi Agostino,

Is it the actual suspend that doesn't work or is it the resume which fails? Per the kernel team's bug policy, can you please attach the following information. Please be sure to attach each file as a separate attachment.

* uname -a > uname-a.log
* cat /proc/version_signature > version.log
* dmesg > dmesg.log
* sudo lspci -vvnn > lspci-vvnn.log

If you are able to, it would be more useful to capture the dmesg output after you attempt to suspend/resume. For more information regarding the kernel team bug policy, please refer to https://wiki.ubuntu.com/KernelTeamBugPolicies . The following might also help: https://wiki.ubuntu.com/DebuggingKernelSuspend . Thanks.

[Agostino Russo (ago)]

Leann

It happends during suspend, not resume (resume might be problematic too, but never went that far).

The issue was present on every kernel/hardware combination I have tried and confirmed by several wubi users. My uneducated guess is that stopping userspace processes such as fuse/ntfs-3g too early is equivalent to ripping off the hard-disk whenever / sits on top of a fuse-mounted device. This is the default setup used by wubi. After suspend it is not possible to issue any normal command. As mentioned, for a better insight I would strongly encourage you to ask mjg59 who already looked at the issue.

Since my current laptop is not too Linux friendly I am concerned that the usual logs would rise a lot of false positives, since as mentioned, the same problem can be replicated on any machine. I will provide a package to replicate the problem based on the latest hardy daily build. In the meantime it is possible to replicate by installing ubuntu 7.10 via http://wubi-installer.org/devel/minefield/Wubi-7.10-alpha-rev386.exe from windows (note that wubi disables suspend, so you will have to re-enable it).

[Agostino Russo (ago)]

Wubi is now available in Hardy Alpha5+, it would be great if some devs in the kernel team could try to suspend from within a wubi installation.

[Leann Ogasawara (leannogasawara)]

Hi Agostino,

It looks like your dmesg cache filled up and the original boot messages were overwritten. Care to try recapturing it? In the mean time I'll reassign to the kernel team to take a look. Thanks.

[Agostino Russo (ago)]

Not sure what happened but now suspend to ram works well in loop installations!

Tested with kernel 2.6.24-11-generic

[Agostino Russo (ago)]

THANKS!

[Launchpad Janitor (janitor)]

Per a decision made by the Ubuntu Kernel Team, bugs will longer be assigned to the ubuntu-kernel-team in Launchpad as part of the bug triage process. The ubuntu-kernel-team is being unassigned from this bug report. Refer to https://wiki.ubuntu.com/KernelTeamBugPolicies for more information. Thanks.

[Christopher Forster (christopherforster)]

Wubi Kubuntu 11.10 Oneiric Ocelot won't resume from suspend. Shows a black screen.