MySQL Bugs: #24124: Bouncing server corrupted .frm file for innodb table

Bug #24124	Bouncing server corrupted .frm file for innodb table
Submitted:	9 Nov 2006 3:26	Modified:	11 Nov 2006 23:21
Reporter:	Ian Flint	Email Updates:
Status:	Not a Bug	Impact on me:	None
Category:	MySQL Server	Severity:	S1 (Critical)
Version:	5.0.24	OS:	Linux (Linux (RHEL4 - 2.6.9-22.0.2.EL))
Assigned to:		CPU Architecture:	Any

Description:
I bounced our mysql server to adjust some parameters, and when it came back up, an innodb table had a corrupt .frm file.

Here are the settings I added:
innodb_flush_log_at_trx_commit=0
innodb_log_buffer_size=8M
innodb_log_file_size=64M
skip_external_locking=1
tmp_table_size=256M
max_heap_table_size=256M

And I deleted the mysql_log_file.

There was an interesting entry in the *.err file when I restarted:

061108 21:04:18  mysqld started
InnoDB: Error: log file ./ib_logfile0 is of different size 0 5242880 bytes
InnoDB: than specified in the .cnf file 0 67108864 bytes!
061108 21:04:19 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.0.24-standard-log'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  MySQL Community Edition - Standard (GPL)

How to repeat:
I hope to never repeat this.

Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://dev.mysql.com/doc/ and the instructions on
how to report a bug at http://bugs.mysql.com/how-to-report.php

What to take care of when changing the log file size is documented in the manual.

This is the excerpt from the log on changing the innodb_log_file_size.  It makes no mention of needing to do anything differently than what I did that resulted in my corrupting the database.  In addition, if a condition like this is known to have a significant risk of corrupting data, shouldn't that prevent the startup of the database?

Excerpt from manual section on innodb_log_file_size:

"The size in bytes of each log file in a log group. The combined size of log files must be less than 4GB on 32-bit computers. The default is 5MB. Sensible values range from 1MB to 1/N-th of the size of the buffer pool, where N is the number of log files in the group. The larger the value, the less checkpoint flush activity is needed in the buffer pool, saving disk I/O. But larger log files also mean that recovery is slower in case of a crash."

I'm changing this back from "Not a Bug" to "Open".  I realize that it very well might be changed back, but to me, it seems like this condition should be very easily preventable.

We're sorry, but the bug system is not the appropriate forum for asking help on using MySQL products. Your problem is not the result of a bug.

Support on using our products is available both free in our forums at http://forums.mysql.com/ and for a reasonable fee direct from our skilled support engineers at http://www.mysql.com/support/

Thank you for your interest in MySQL.

See: http://dev.mysql.com/doc/refman/4.1/en/adding-and-removing.html last paragraph