OS errno 24 - Too many open files
使用xtrabackup备份时候报错
210716 08:49:48 [01] Copying ./ecology/workrelate_share_permissions.ibd to /backupmysql/data/ecology/workrelate_share_permissions.ibd
xtrabackup: Can't create/write to file '/backupmysql/data/ecology/' (OS errno 24 - Too many open files)
[02] xtrabackup: error: cannot open the destination stream for ecology/
[02] xtrabackup: Error: xtrabackup_copy_datafile() failed.
[02] xtrabackup: Error: failed to copy datafile.
210716 08:49:48 [01] ...done
210716 08:49:48 [03] ...done
210716 08:49:49 >> log scanned up to (515003610)
1.使用ulimit -a 查看shell资源限制，发现open files 限制为1024
[root@eslave01 ~]# ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 96272
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 96272
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
[root@eslave01 ~]# ulimit -n
1024
2.登录mysql 查看最大连接数，也被限定在214,配置文件设定的是5120但没有生效
[root@slave01 ~]# mysql -uroot -p
mysql> show global variables like 'max_connec%';
+--------------------+---------+
| Variable_name | Value |
+--------------------+---------+
| max_connect_errors | 1000000 |
| max_connections | 214 |
+--------------------+---------+
4 rows in set (0.01 sec)
mysql> system grep -i max_connections /etc/
max_connections = 5120
3.分别修改 和 打开的文件描述符的限制
[root@eslave01 ~]# grep -i nofile /etc/security/
# - nofile - max number of open file descriptors
[root@eslave01 ~]# vi /etc/security/
* hard nofile 65535
* soft nofile 65535
[root@slave01]# vi /etc/
添加
[Service]
LimitNOFILE = 65535
LimitNPROC = 65535
4.重新登录会话
[root@slave01]# ulimit -n
65535
[root@slave01]# su - mysql
上一次登录：五 7月 16 08:50:22 CST 2021pts/1 上
[mysql@emaster ~]$ ulimit -n
65535
5.重启mysql
[root@slave01]# mysqld_safe --defaults-file=/etc/ > /mysql/errorlog/ 2>&1 &
6.再次查看最大打开连接数和文件限制
mysql> show global variables like 'max_connec%';
+--------------------+---------+
| Variable_name | Value |
+--------------------+---------+
| max_connect_errors | 1000000 |
| max_connections | 5120 |
+--------------------+---------+
mysql> show global variables like "%open_files_limit%";
+------------------+-------+
| Variable_name | Value |
+------------------+-------+
| open_files_limit | 65535 |
+------------------+-------+
7.重新开始备份,备份成功
[root@slave01 data]# xtrabackup --defaults-file=/etc/ --host=192.168.200.147 --user=root --password=mysql123 --port=3306 --backup --parallel=3 --target-dir=/backupmysql/data
MySQL binlog position: filename 'mysql-bin.000019', position '272', GTID of the last change '11408e8c-e297-11eb-b003-0050568d7647:1-666,4597305d-e297-11eb-989c-0050568d551d:1-47401,dbcabeff-e296-11eb-8c0f-0050568d200a:1-54670'
210716 09:05:08 [00] Writing /backupmysql/data/
210716 09:05:08 [00] ...done
210716 09:05:08 [00] Writing /backupmysql/data/xtrabackup_info
210716 09:05:08 [00] ...done
xtrabackup: Transaction log of lsn (515535895) to (515565651) was copied.
210716 09:05:09 completed OK!
