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[rhpot1991 <rhpot1991@xxxxxxxxxx>]

Public bug reported:

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

Example:
Total DISK READ:       3.80 K/s | Total DISK WRITE:     322.99 K/s
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN     IO>    COMMAND                                                                
  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.

** Affects: mythtv (Ubuntu)
     Importance: Undecided
         Status: New

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https://bugs.launchpad.net/bugs/997367

Title:
  mythfilldatabase takes hours to complete

Status in “mythtv” package in Ubuntu:
  New

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

  Example:
  Total DISK READ:       3.80 K/s | Total DISK WRITE:     322.99 K/s
    TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN     IO>    COMMAND                                                                
    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.

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