innobackupex:Error:xtrabackup child process has died at /usr/bin/innobackupex

使用innobackupex进行数据库备份,报如下错误：
innobackupex --compress --parallel=4  --user=root  --password=yoon /export/backup/
xtrabackup_56 version 2.1.9 for MySQL server 5.6.17 Linux (x86_64) (revision id: 744)
xtrabackup: uses posix_fadvise().
xtrabackup: cd to /var/lib/mysql
xtrabackup: open files limit requested 0, set to 1024
xtrabackup: using the following InnoDB configuration:
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 = 50331648
2016-01-21 21:41:29 7f343333b720  InnoDB: Operating system error number 2 in a file operation.
InnoDB: The error means the system cannot find the path specified.
InnoDB: File ./ib_logfile0: 'open' returned OS error 71. Cannot continue operation
innobackupex: Error: The xtrabackup child process has died at /usr/bin/innobackupex line 2622.

在生产库备份没问题，在虚拟机备份就出问题！

percona说修改配置文件路径权限：
https://www.percona.com/forums/questions-discussions/percona-xtrabackup/13396-file-name-ib_logfile0-innodb-file-operation-call-open-returned-os-error-71
[root@hank-yoon mysql]# ls -ltr
total 180
-rw-r--r--.  1 root root   2496 Jul 15  2015 README
-rw-r--r--.  1 root root  17987 Jul 15  2015 COPYING
-rw-r--r--.  1 root root 104897 Jul 15  2015 INSTALL-BINARY
drwxr-xr-x.  2 root root   4096 Dec 19 18:39 docs
drwxr-xr-x.  3 root root   4096 Dec 19 18:39 include
drwxr-xr-x.  4 root root   4096 Dec 19 18:39 man
drwxr-xr-x.  3 root root   4096 Dec 19 18:39 data
drwxr-xr-x.  3 root root   4096 Dec 19 18:39 lib
drwxr-xr-x.  2 root root   4096 Dec 19 18:39 scripts
drwxr-xr-x.  2 root root   4096 Dec 19 18:39 bin
drwxr-xr-x. 10 root root   4096 Dec 19 18:39 mysql-test
drwxr-xr-x.  2 root root   4096 Dec 19 18:39 support-files
drwxr-xr-x. 28 root root   4096 Dec 19 18:39 share
drwxr-xr-x.  4 root root   4096 Dec 19 18:39 sql-bench
-rw-r--r--.  1 root root    943 Dec 19 18:39 my.cnf
drwxr-xr-x.  2 root root   4096 Dec 19 18:40 etc
[root@hank-yoon mysql]# chown -R mysql.mysql etc/     问题依旧！

报错总是提示ib_logfile0,在配置文件中ib_logfile参数是存在的：
InnoDB: File ./ib_logfile0: 'open' returned OS error 71. Cannot continue operation

重新备份指定参数文件：
[root@hank-yoon backup]# innobackupex --compress --parallel=4 --defaults-file=/export/servers/mysql/etc/my.cnf  --user=root  --password=yoon /export/backup/

InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona LLC and/or its affiliates 2009-2013.  All Rights Reserved.

This software is published under
the GNU GENERAL PUBLIC LICENSE Version 2, June 1991.

Get the latest version of Percona XtraBackup, documentation, and help resources:
http://www.percona.com/xb/p

160121 22:12:52  innobackupex: Connecting to MySQL server with DSN 'dbi:mysql:;mysql_read_default_file=/export/servers/mysql/etc/my.cnf;mysql_read_default_group=xtrabackup' as 'root'  (using password: YES).
160121 22:12:52  innobackupex: Connected to MySQL server
160121 22:12:52  innobackupex: Executing a version check against the server...
160121 22:12:52  innobackupex: Done.
IMPORTANT: Please check that the backup run completes successfully.
           At the end of a successful backup run innobackupex
           prints "completed OK!".

innobackupex: Using mysql server version 5.6.26-log

innobackupex: Created backup directory /export/backup/2016-01-21_22-12-52

160121 22:12:52  innobackupex: Starting ibbackup with command: xtrabackup_56  --defaults-file="/export/servers/mysql/etc/my.cnf"  --defaults-group="mysqld" --backup --suspend-at-end --target-dir=/export/backup/2016-01-21_22-12-52 --tmpdir=/export/data/mysql/tmp --compress --compress-threads=1 --parallel=4
innobackupex: Waiting for ibbackup (pid=5476) to suspend
innobackupex: Suspend file '/export/backup/2016-01-21_22-12-52/xtrabackup_suspended_2'

xtrabackup_56 version 2.1.9 for MySQL server 5.6.17 Linux (x86_64) (revision id: 744)
xtrabackup: uses posix_fadvise().
xtrabackup: cd to /export/data/mysql/data/
xtrabackup: open files limit requested 65535, set to 65535
xtrabackup: using the following InnoDB configuration:
xtrabackup:   innodb_data_home_dir = /export/data/mysql/data
xtrabackup:   innodb_data_file_path = ibdata1:2G;ibdata2:2G:autoextend
xtrabackup:   innodb_log_group_home_dir = /export/data/mysql/data
xtrabackup:   innodb_log_files_in_group = 3
xtrabackup:   innodb_log_file_size = 268435456
2016-01-21 22:12:52 7fa03bee9720 InnoDB: Using Linux native AIO
xtrabackup: using O_DIRECT
>> log scanned up to (1510934)
InnoDB: Opened 4 undo tablespaces
xtrabackup: Starting 4 threads for parallel data files transfer
[04] Compressing /export/data/mysql/data/ibdata1 to /export/backup/2016-01-21_22-12-52/ibdata1.qp
[03] Compressing /export/data/mysql/data/ibdata2 to /export/backup/2016-01-21_22-12-52/ibdata2.qp
[02] Compressing /export/data/mysql/undo/undo001 to /export/backup/2016-01-21_22-12-52/undo001.qp
[01] Compressing /export/data/mysql/undo/undo002 to /export/backup/2016-01-21_22-12-52/undo002.qp
[02]        ...done
[01]        ...done
>> log scanned up to (1510934)
[01] Compressing /export/data/mysql/undo/undo003 to /export/backup/2016-01-21_22-12-52/undo003.qp
[02] Compressing /export/data/mysql/undo/undo004 to /export/backup/2016-01-21_22-12-52/undo004.qp
[02]        ...done
[01]        ...done
[02] Compressing ./mysql/innodb_index_stats.ibd to /export/backup/2016-01-21_22-12-52/mysql/innodb_index_stats.ibd.qp
[02]        ...done
[01] Compressing ./mysql/innodb_table_stats.ibd to /export/backup/2016-01-21_22-12-52/mysql/innodb_table_stats.ibd.qp
[01]        ...done
[02] Compressing ./mysql/slave_master_info.ibd to /export/backup/2016-01-21_22-12-52/mysql/slave_master_info.ibd.qp
[02]        ...done
>> log scanned up to (1510934)
[01] Compressing ./mysql/slave_relay_log_info.ibd to /export/backup/2016-01-21_22-12-52/mysql/slave_relay_log_info.ibd.qp
[01]        ...done
[02] Compressing ./mysql/slave_worker_info.ibd to /export/backup/2016-01-21_22-12-52/mysql/slave_worker_info.ibd.qp
[02]        ...done
>> log scanned up to (1510934)
>> log scanned up to (1510934)
>> log scanned up to (1510934)
>> log scanned up to (1510934)
[04]        ...done
[03]        ...done
xtrabackup: Creating suspend file '/export/backup/2016-01-21_22-12-52/xtrabackup_suspended_2' with pid '5476'

160121 22:12:59  innobackupex: Continuing after ibbackup has suspended
160121 22:12:59  innobackupex: Starting to lock all tables...
160121 22:12:59  innobackupex: All tables locked and flushed to disk

160121 22:12:59  innobackupex: Starting to backup non-InnoDB tables and files
innobackupex: in subdirectories of '/export/data/mysql/data/'
innobackupex: Backing up files '/export/data/mysql/data//mysql/*.{frm,isl,MYD,MYI,MAD,MAI,MRG,TRG,TRN,ARM,ARZ,CSM,CSV,opt,par}' (74 files)
>> log scanned up to (1510934)
innobackupex: Backing up files '/export/data/mysql/data//performance_schema/*.{frm,isl,MYD,MYI,MAD,MAI,MRG,TRG,TRN,ARM,ARZ,CSM,CSV,opt,par}' (53 files)
160121 22:13:00  innobackupex: Finished backing up non-InnoDB tables and files

160121 22:13:00  innobackupex: Waiting for log copying to finish

xtrabackup: The latest check point (for incremental): '1510934'
xtrabackup: Stopping log copying thread.
.>> log scanned up to (1510934)

xtrabackup: Creating suspend file '/export/backup/2016-01-21_22-12-52/xtrabackup_log_copied' with pid '5476'
xtrabackup: Transaction log of lsn (1510934) to (1510934) was copied.
160121 22:13:01  innobackupex: All tables unlocked

innobackupex: Backup created in directory '/export/backup/2016-01-21_22-12-52'
innobackupex: MySQL binlog position: filename 'mysql-bin.000007', position 120
160121 22:13:01  innobackupex: Connection to database server closed
160121 22:13:01  innobackupex: completed OK!