在各种内存CPU核心只有1/2核，内存只有512M/1G的vps下，内存、CPU、硬盘都不是太充裕。因此主要思路是，禁止吃内存大户innodb引擎，默认使用MyISAM。禁止吃硬盘大户log-bin，再调节一些参数到合适的数值。
[mysql] # CLIENT #
port = 3306
socket = /var/run/mysqld/mysqld.sock [mysqld] # GENERAL #
user = mysql
default-storage-engine = MyISAM
default-tmp-storage-engine = MYISAM
socket = /var/run/mysqld/mysqld.sock
pid-file = /var/run/mysqld/mysqld.pid
bind-address = 127.0.0.1
lc-messages-dir = /usr/share/mysql/
skip-external-locking # MyISAM #
key-buffer-size = 16M
myisam-recover = FORCE,BACKUP # SAFETY #
max-allowed-packet = 16M
max-connect-errors = 256
skip-name-resolve
sysdate-is-now = 1 # DATA STORAGE #
datadir = /var/lib/mysql/ # CACHES AND LIMITS #
tmp-table-size = 32M
max-heap-table-size = 32M
query-cache-type = 0
query-cache-size = 0
max-connections = 64
thread-stack = 192K
thread-cache-size = 4
thread-concurrency = 2
open-files-limit = 1028
table-definition-cache = 256
table-open-cache = 64 # INNODB #
loose-skip-innodb
loose-innodb-trx = 0
loose-innodb-locks = 0
loose-innodb-lock-waits = 0
loose-innodb-cmp = 0
loose-innodb-cmp-per-index = 0
loose-innodb-cmp-per-index-reset = 0
loose-innodb-cmp-reset = 0
loose-innodb-cmpmem = 0
loose-innodb-cmpmem-reset = 0
loose-innodb-buffer-page = 0
loose-innodb-buffer-page-lru = 0
loose-innodb-buffer-pool-stats = 0
loose-innodb-metrics = 0
loose-innodb-ft-default-stopword = 0
loose-innodb-ft-inserted = 0
loose-innodb-ft-deleted = 0
loose-innodb-ft-being-deleted = 0
loose-innodb-ft-config = 0
loose-innodb-ft-index-cache = 0
loose-innodb-ft-index-table = 0
loose-innodb-sys-tables = 0
loose-innodb-sys-tablestats = 0
loose-innodb-sys-indexes = 0
loose-innodb-sys-columns = 0
loose-innodb-sys-fields = 0
loose-innodb-sys-foreign = 0
loose-innodb-sys-foreign-cols = 0 # LOGGING #
log-error = /var/log/mysql/error.log
log-queries-not-using-indexes = 0
long-query-time = 1
slow-query-log = 1
slow-query-log-file = /var/log/mysql/slow.log
重启后mysql的内存占用大概为70M+，其中和内存关系较大的是key-buffer-size、tmp-table-size和thread-cache-size属性，作用分别为缓存MyISAM的索引、执行Group By之类语言时使用的临时表内存空间、查询线程。
配置的使用环境为percona server 5.6，其他版本的mysql没有测试。