Operating system error number 17 when use parallel backup

[yczealot]

111128 02:18:13 innobackupex: Starting ibbackup with command: xtrabackup_55 --defaults-file="/data1/mysql4554/my4554.cnf.bakuse" --backup --suspend-at-end --target-dir=/baknfs1/backup/day/mysql4554/20111128/mysql4554 --throttle=1000 --parallel=4
innobackupex: Waiting for ibbackup (pid=16571) to suspend
innobackupex: Suspend file '/baknfs1/backup/day/mysql4554/20111128/mysql4554/xtrabackup_suspended'

xtrabackup: uses posix_fadvise().
xtrabackup: cd to /data1/mysql4554
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 = 3
xtrabackup: innodb_log_file_size = 1363148800
111128 2:18:13 InnoDB: Using Linux native AIO
xtrabackup: use O_DIRECT
111128 2:18:13 InnoDB: Warning: allocated tablespace 3192, old maximum was 9
>> log scanned up to (619544778885)
111128 2:18:24 InnoDB: Operating system error number 17 in a file operation.
InnoDB: Error number 17 means 'File exists'.
InnoDB: Some operating system error numbers are described at
InnoDB: http://dev.mysql.com/doc/refman/5.5/en/operating-system-error-codes.html
[01] xtrabackup: error: cannot open /baknfs1/backup/day/mysql4554/20111128/mysql4554/relation_7/relation_376.ibd
[01] xtrabackup: Error: xtrabackup_copy_datafile() failed.
[01] xtrabackup: Error: failed to copy datafile.
xtrabackup_55 version 1.6.3 for Percona Server 5.5.9 Linux (x86_64) (revision id: 292)
xtrabackup: Starting 4 threads for parallel data files transfer
[03] Copying ./relation_7/relation_376.ibd
     to /baknfs1/backup/day/mysql4554/20111128/mysql4554/relation_7/relation_376.ibd
[02] Copying ./ibdata1
     to /baknfs1/backup/day/mysql4554/20111128/mysql4554/ibdata1
innobackupex: Error: ibbackup child process has died at /usr/bin/innobackupex line 343.

-----------------------------
I use xtrabackup to backup more than 50 databases , I find one or two databases backup failed almost everyday ,and they aren't same one.
I guess this due to the parallel parameter.Could you give me some advice?

[yczealot (yczealot)]

another example:

111201 03:58:20 innobackupex: Starting ibbackup with command: xtrabackup_55 --defaults-file="/data1/mysql4133/my4133.cnf.bakuse" --backup --suspend-at-end --target-dir=/baknfs1/backup/day/mysql4133/20111201/mysql4133 --throttle=1000 --parallel=4
innobackupex: Waiting for ibbackup (pid=10535) to suspend
innobackupex: Suspend file '/baknfs1/backup/day/mysql4133/20111201/mysql4133/xtrabackup_suspended'

xtrabackup: uses posix_fadvise().
xtrabackup: cd to /data1/mysql4133
xtrabackup: Target instance is assumed as followings.
xtrabackup: innodb_data_home_dir = ./
xtrabackup: innodb_data_file_path = ibdata1:100M:autoextend
xtrabackup: innodb_log_group_home_dir = ./
xtrabackup: innodb_log_files_in_group = 3
xtrabackup: innodb_log_file_size = 134217728
111201 3:58:20 InnoDB: Using Linux native AIO
xtrabackup: use O_DIRECT
111201 3:58:21 InnoDB: Warning: allocated tablespace 2219, old maximum was 9
>> log scanned up to (33005021)
111201 3:58:21 InnoDB: Operating system error number 17 in a file operation.
InnoDB: Error number 17 means 'File exists'.
InnoDB: Some operating system error numbers are described at
InnoDB: http://dev.mysql.com/doc/refman/5.5/en/operating-system-error-codes.html
[02] xtrabackup: error: cannot open /baknfs1/backup/day/mysql4133/20111201/mysql4133/mytv_user_playlist/stv_user_playlist_aa.ibd
[02] xtrabackup: Error: xtrabackup_copy_datafile() failed.
[02] xtrabackup: Error: failed to copy datafile.
xtrabackup_55 version 1.6.3 for Percona Server 5.5.9 Linux (x86_64) (revision id: 292)
xtrabackup: Starting 4 threads for parallel data files transfer
[03] Copying ./mytv_user_playlist/stv_user_playlist_aa.ibd
     to /baknfs1/backup/day/mysql4133/20111201/mysql4133/mytv_user_playlist/stv_user_playlist_aa.ibd
[04] Copying ./mytv_user_playlist/stv_user_playlist_f3.ibd
     to /baknfs1/backup/day/mysql4133/20111201/mysql4133/mytv_user_playlist/stv_user_playlist_f3.ibd
innobackupex: Error: ibbackup child process has died at /usr/bin/innobackupex line 343.

[Alexey Kopytov (akopytov)]

Probably a duplicate of bug #826632.

[Stewart Smith (stewart)]

Setting as confirmed as we are seeing existing failures and have test cases. After bug #826632 is fixed, we can check if it also fixes this.

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PXB-583