I was just trying to take a hot backup with innobackupex but I get a read error whilst xtrabackup is trying to scan the log - strangely though the failure is an Error 0 which is reported as a success. Versions as follows:
InnoDB Backup Utility v1.5.1-xtrabackup;
Xtrabackup_55 version 1.6.3 for Percona Server 5.5.9
[/LIST] Error output looks like this:
xtrabackup_55 version 1.6.3 for Percona Server 5.5.9 Linux (x86_64) (revision id: undefined) xtrabackup: uses posix_fadvise(). xtrabackup: cd to /var/lib/mysql xtrabackup: Target instance is assumed as followings. xtrabackup: innodb_data_home_dir = ./ xtrabackup: innodb_data_file_path = ibdata1:10M:autoextend xtrabackup: innodb_log_group_home_dir = ./ xtrabackup: innodb_log_files_in_group = 2 xtrabackup: innodb_log_file_size = 5242880 141216 10:59:08 InnoDB: Using Linux native AIO 141216 10:59:08 InnoDB: Warning: allocated tablespace 53, old maximum was 9 >> log scanned up to (1221137553871)  Copying ./ibdata1 to /home/nick/2014-12-16_10-59-04/ibdata1 >> log scanned up to (1221137615178) >> log scanned up to (1221137624351) >> log scanned up to (1221137650292) InnoDB: Error: tried to read 1048576 bytes at offset 0 534773760. InnoDB: Was only able to read 40960. 141216 11:00:15 InnoDB: Operating system error number 0 in a file operation. InnoDB: Error number 0 means 'Success'. InnoDB: Some operating system error numbers are described at InnoDB: http://dev.mysql.com/doc/refman/5.5/en/operating-system-error-codes.html InnoDB: File operation call: 'read'. InnoDB: Cannot continue operation. innobackupex: Error: ibbackup child process has died at /usr/bin/innobackupex line 336.
Can anyone shed any light on what causes this? MySQL is using this Inno DB normally without any apparent errors, and starts up and shuts down normally when required, so I was assuming that the integrity of the data files + logs was ok, but perhaps not? Is this a known issue with xtrabackup? Is there a workaround or some way to get more information on this issue?