mythfilldatabase takes hours to complete

Bug #997367 reported by rhpot1991 on 2012-05-09
This bug affects 2 people
Affects Status Importance Assigned to Milestone
mythtv (Ubuntu)

Bug Description

Background: 12.04 went to MySQL 5.5, which uses InnoDB by default. So temp tables created by mythfilldatabase are now innodb instead of myisam. These temp tables get written to disk at /var/lib/mysql. Because these temp tables are written to disk the ext4 journaler constantly runs against these files, causing a massive IO block.

How to reproduce:
1. run: mythfilldatabase --refresh all
2. check iotop

Total DISK READ: 3.80 K/s | Total DISK WRITE: 322.99 K/s
  329 be/3 root 0.00 B/s 0.00 B/s 0.00 % 99.50 % [jbd2/sda1-8]
1091 be/4 mysql 3.80 K/s 83.60 K/s 0.00 % 0.34 % mysqld

In the past this process would run in a few minutes, with this IO blocking going on it takes hours.

rhpot1991 (rhpot1991) wrote :


john@ultramagnus:~$ dpkg -l |grep mythtv
ii libmythtv-perl 2:0.25.0+fixes.20120508.b9e60ff-0ubuntu0mythbuntu4 A PERL library to access some MythTV features
ii mythtv 2:0.25.0+fixes.20120508.b9e60ff-0ubuntu0mythbuntu4 A personal video recorder application (client and server)
ii mythtv-backend 2:0.25.0+fixes.20120508.b9e60ff-0ubuntu0mythbuntu4 A personal video recorder application (server)
ii mythtv-backend-master 2:0.25.0+fixes.20120508.b9e60ff-0ubuntu0mythbuntu4 Metapackage to setup and configure a "Master Backend" profile of MythTV.
ii mythtv-common 2:0.25.0+fixes.20120508.b9e60ff-0ubuntu0mythbuntu4 A personal video recorder application (common data)
ii mythtv-database 2:0.25.0+fixes.20120508.b9e60ff-0ubuntu0mythbuntu4 A personal video recorder application (database)
ii mythtv-frontend 2:0.25.0+fixes.20120508.b9e60ff-0ubuntu0mythbuntu4 A personal video recorder application (client)
ii mythtv-status 0.9.3-1 Show the status of a MythTV backend
ii mythtv-theme-mythbuntu 2:0.25.0+fixes.20120508.b9e60ff-0ubuntu0mythbuntu4 The mythbuntu MythTV Theme
ii mythtv-transcode-utils 2:0.25.0+fixes.20120508.b9e60ff-0ubuntu0mythbuntu4 Utilities used for transcoding MythTV tasks
ii php-mythtv 2:0.25.0+fixes.20120508.b9e60ff-0ubuntu0mythbuntu4 PHP Bindings for MythTV

rhpot1991 (rhpot1991) wrote :

Temporary fix:

Add "default-storage-engine=MyISAM"
to /etc/mysql/mythtv.cnf

This is not a great fix as it will set the default to MyISAM for the entire MySQL instance.

rhpot1991 (rhpot1991) on 2012-05-10
Changed in mythtv (Ubuntu):
status: New → Confirmed
Karl Dietz (dekarl) wrote :

A fix has been commited to 0.25-fixes on the 28th and is available via the updates PPA

Changed in mythtv (Ubuntu):
status: Confirmed → Fix Committed
rhpot1991 (rhpot1991) wrote :

Confirmed this issue is fixed.

Changed in mythtv (Ubuntu):
status: Fix Committed → Fix Released

Hello rhpot1991, or anyone else affected,

Accepted mythtv into precise-proposed. The package will build now and be available at in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please change the bug tag from verification-needed to verification-done. If it does not, change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at . Thank you in advance!

Changed in mythtv (Ubuntu Precise):
status: New → Fix Committed
tags: added: verification-needed
Thomas Mashos (tgm4883) wrote :

Tested and works great for me.

tags: added: verification-done
removed: verification-needed

The verification of this Stable Release Update has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regresssions.

Launchpad Janitor (janitor) wrote :

This bug was fixed in the package mythtv - 2:0.25.2+fixes.20120802.46cab93-0ubuntu1

mythtv (2:0.25.2+fixes.20120802.46cab93-0ubuntu1) precise-proposed; urgency=low

  * New upstream fixes branch checkout (46cab93)
  * Updated to 0.25.2 point release. (LP: #1029522)
  * Major fixes:
    - Mythfilldatabase takes hours instead of minutes to run (LP: #997367)
    - A popular tuner card doesn't record in digital cable mode (trac 10712)
  * fix get-orig-source rule's broken tarball fetch from archive.
  * Enable libcec support (LP: #982272)
  * Add missingok to additional mythtv-backend logs. (LP: #982162)
  * Pull an updated snapshot of Mythbuntu theme, to avoid theme
    downloader telling the user there is an updated theme on first
  * Update amejia's email on uploaders field.
  * Drop recommends on adept-notifier.
  * Bump standards version.
  * New upstream checkout (25dd4ce)
 -- Mario Limonciello <email address hidden> Wed, 08 Aug 2012 20:32:13 -0500

Changed in mythtv (Ubuntu Precise):
status: Fix Committed → Fix Released
To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers