btrfs blocked several minutes in btrfs-transacti

[Jeffery von Ronne]

When I first boot up and log into the system, unity takes several minutes to load after I enter my username and password (showing just my wallpaper image). When I look at /var/log/kern.log , I see multiple occurrences of the message,
"INFO: task btrfs-transacti:379 blocked for more than 120 seconds" with a stack trace. (see attached /var/log/kern.lorg)

It may or may not be relevant that my home directory is on ecryptfs, my swap is 16GB and encrypted (but doesn't seem to be being used during boot up).

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.8.0-29-generic 3.8.0-29.42~precise1
ProcVersionSignature: Ubuntu 3.8.0-29.42~precise1-generic 3.8.13.5
Uname: Linux 3.8.0-29-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.4
Architecture: amd64
Date: Tue Sep 3 17:24:15 2013
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: linux-lts-raring
UpgradeStatus: No upgrade log present (probably fresh install)

[Jeffery von Ronne (vonronne)]

Is there away to attach my kern.log so that it, it is private to the Canonical bug triaging team?

[Jeffery von Ronne (vonronne)]

iotop shows the kernel threads btrfs-cache-1 and btrfs-cache-2 constantly reading approximately 1M/s from the disk for the first several minutes after it boots up.
As workarounds, I've tried moving /var/log to its won partition, enabling btrfs's space_cache option, and disabling zeitgeist. Subjectively, these seem to have helped some, and I didn't see any messages about btrfs-transaction being blocked for more than 120s on my last boot, but the system still takes 5 minutes from startup before I can login and start running programs in unity.

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1220469

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Jeffery von Ronne (vonronne)]

I have since upgraded from precise to trusty and made several other tweaks to improve btrfs performance, so I can no longer provide any additional log files for the system as it was when btrfs blocked for several minutes.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.14 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.14-trusty/

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]