系统根目录可用空间低于20%，清理mysql binary logs日志空间
随着平台运行时间的增加，mysql二进制日志会占用大量的空间，使得
ceph告警，/根目录可用空间低于20%，所以此时要清理空间。
[root@node-1 lib]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/os-root 138G 99G 32G 76% /
tmpfs 16G 22M 16G 1% /dev/shm
/dev/sda3 194M 28M 156M 16% /boot
/dev/mapper/mongo-mongodb
121G 32G 84G 28% /var/lib/mongo
[root@node-1 lib]# cd /var/lib/
[root@node-1 lib]# du -sh ./*
24K ./alternatives
52K ./astute
8.0K ./authconfig
16K ./ceilometer
313M ./ceph
8.0K ./cinder
8.0K ./corosync
4.0K ./dav
8.0K ./dbus
4.0K ./dhclient
4.0K ./dnsmasq
4.0K ./games
186M ./ganglia
2.1G ./glance
4.0K ./haproxy
4.0K ./heat
4.0K ./hiera
28K ./iscsi
8.0K ./keystone
4.0K ./libvirt
8.0K ./logrotate.status
4.0K ./misc
2.7M ./mlocate
32G ./mongo
4.0K ./mongodb
24G ./mysql
4.0K ./net-snmp
328K ./neutron
28K ./nfs
92K ./nova
8.0K ./ntp
4.0K ./openstack-dashboard
8.0K ./openvswitch
37M ./pacemaker
8.0K ./php
8.0K ./plymouth
28K ./polkit-1
8.0K ./postfix
2.6M ./puppet
448K ./rabbitmq
4.0K ./random-seed
43M ./rpm
4.0K ./rsyslog
16K ./samba
12K ./stateless
4.0K ./swift
8.0K ./udev
12M ./yum
[root@node-1 lib]# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 561143
Server version: 5.6.16-log MySQL Community Server (GPL), wsrep_25.5.rXXXX
Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show binary logs
-> ;
+------------------+------------+
| Log_name | File_size |
+------------------+------------+
| mysql-bin.000001 | 65309 |
| mysql-bin.000002 | 1050551 |
| mysql-bin.000003 | 143 |
| mysql-bin.000004 | 3540294 |
| mysql-bin.000005 | 143 |
| mysql-bin.000006 | 3003498 |
| mysql-bin.000007 | 143 |
| mysql-bin.000008 | 1860503 |
| mysql-bin.000009 | 143 |
| mysql-bin.000010 | 44957 |
| mysql-bin.000011 | 143 |
| mysql-bin.000012 | 3382 |
| mysql-bin.000013 | 143 |
| mysql-bin.000014 | 79842271 |
| mysql-bin.000015 | 143 |
| mysql-bin.000016 | 546006 |
| mysql-bin.000017 | 143 |
| mysql-bin.000018 | 1073742179 |
| mysql-bin.000019 | 1073742802 |
| mysql-bin.000020 | 1073744465 |
| mysql-bin.000021 | 1073742189 |
| mysql-bin.000022 | 1073742449 |
| mysql-bin.000023 | 1073742099 |
| mysql-bin.000024 | 1073742227 |
| mysql-bin.000025 | 1073742421 |
| mysql-bin.000026 | 1073742434 |
| mysql-bin.000027 | 1073744436 |
| mysql-bin.000028 | 1073741968 |
| mysql-bin.000029 | 1073742232 |
| mysql-bin.000030 | 1073741967 |
| mysql-bin.000031 | 1073742139 |
| mysql-bin.000032 | 1073742557 |
| mysql-bin.000033 | 1073741954 |
| mysql-bin.000034 | 1073741886 |
| mysql-bin.000035 | 1073742119 |
| mysql-bin.000036 | 967440665 |
| mysql-bin.000037 | 143 |
| mysql-bin.000038 | 1073742079 |
| mysql-bin.000039 | 1073742755 |
| mysql-bin.000040 | 1073742013 |
| mysql-bin.000041 | 1073742194 |
| mysql-bin.000042 | 721149061 |
+------------------+------------+
42 rows in set (0.00 sec)
//删除mysql bin-log日志，删除binlog.000038之前的，不包括binlog.000038//
mysql> purge binary logs to 'mysql-bin.000038';
Query OK, 0 rows affected (1.33 sec)
mysql> show binary logs;
+------------------+------------+
| Log_name | File_size |
+------------------+------------+
| mysql-bin.000038 | 1073742079 |
| mysql-bin.000039 | 1073742755 |
| mysql-bin.000040 | 1073742013 |
| mysql-bin.000041 | 1073742194 |
| mysql-bin.000042 | 721266404 |
+------------------+------------+
5 rows in set (0.00 sec)
mysql> exit
Bye
[root@node-1 lib]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/os-root 138G 80G 51G 62% /
tmpfs 16G 22M 16G 1% /dev/shm
/dev/sda3 194M 28M 156M 16% /boot
/dev/mapper/mongo-mongodb
121G 32G 84G 28% /var/lib/mongo
