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From:Heikki Tuuri Date:March 22 2004 1:20pm
Subject:Re: InnoDB Hot Backup problems with O_DIRECT (ibbackup)
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Hi!

Looks like your Linux kernel makes the file read performed by ibbackup to
fail immediately, but does not set errno to anything. That is why ibbackup
says the errno is 0.

The support for O_DIRECT is rather new in Linux kernels.

For now the workaround is not to use O_DIRECT if you plan to use ibbackup. I
hope Linux kernels 2.6 will fix this issue, since the file i/o system is
modified in it, but I have not tested it.

Best regards,

Heikki
Innobase Oy
InnoDB - transactions, row level locking, and foreign keys for MySQL
InnoDB Hot Backup - a hot backup tool for InnoDB which also backs up MyISAM
tables
http://www.innodb.com/order.php

Register now for the 2004 MySQL Users Conference!
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List: MySQL General Discussion« Previous MessageNext Message »
From:queritorDate:March 20 2004 3:22am
Subject: InnoDB Hot Backup problems with O_DIRECT (ibbackup)



I'm having the following problem while trying to run ibbackup when the
database is using innodb_flush_method=O_DIRECT
This is on Redhat Enterprise 3.0.
As you can see, it's reporting an error code of 0, which supposedly means
'success'

Is there a way around this or will I have to use another file flush
method?

Thanks
------ START OUTPUT -------
[root@apollo mysql-hotbak]# ibbackup --compress /etc/my.cnf
/var/mysql-hotbak/myhotbak.cnf
InnoDB Hot Backup version 2.0-beta5; Copyright 2003 Innobase Oy
License xxxxxx is granted to xxxxx@stripped xxxxx xxxxxxxx
(--apply-log works in any computer regardless of the hostname)
Licensed for use in a computer whose hostname is 'apollo'
Expires 0000-0-0 (year-month-day) at 00:00
See http://www.innodb.com for further information
Type ibbackup --license for detailed license terms, --help for help

Contents of /etc/my.cnf:
innodb_data_home_dir got value /var/lib/mysql/
innodb_data_file_path got value
ibdata01:2000M;ibdata02:2000M;ibdata03:2000M;ibdata04:2000M;ibdata05:2000M
datadir got value /var/lib/mysql
innodb_log_group_home_dir got value /var/lib/mysql/
innodb_log_files_in_group got value 3
innodb_log_file_size got value 67108864

Contents of /var/mysql-hotbak/myhotbak.cnf:
innodb_data_home_dir got value /var/mysql-hotbak
innodb_data_file_path got value
ibdata01:2000M;ibdata02:2000M;ibdata03:2000M;ibdata04:2000M;ibdata05:2000M
datadir got value /var/mysql-hotbak
innodb_log_group_home_dir got value /var/mysql-hotbak
innodb_log_files_in_group got value 3
innodb_log_file_size got value 67108864

ibbackup: Found checkpoint at lsn 3 246406950
ibbackup: Starting log scan from lsn 3 246406656
040320  2:01:41  ibbackup: Copying log...
040320  2:01:41  ibbackup: Log copied, lsn 3 246406950
ibbackup: We wait 10 seconds before starting copying the data files...
040320  2:01:51  ibbackup: Copying /var/lib/mysql/ibdata01
040320  2:02:01  InnoDB: Operating system error number 0 in a file
operation.
InnoDB: Error number 0 means 'Success'.
InnoDB: See also section 13.2 at http://www.innodb.com/ibman.html
InnoDB: about operating system error numbers.
InnoDB: File operation call: 'read'.
InnoDB: Cannot continue operation.
----- END OUTPUT -------

Thread
InnoDB Hot Backup problems with O_DIRECT (ibbackup)queritor20 Mar
Re: InnoDB Hot Backup problems with O_DIRECT (ibbackup)Heikki Tuuri22 Mar