We have a server that runs both mysql version 4 (for legacy support) and mysql 5 on a dual processor machine. When the /etc/init.d/mysqld start command is issued, mysql takes 100% of one of the CPUs for 10 seconds or so, then shifts to taking 100% of the other, then repeats the cycle. mysql is never available.
here is the my.cnf from /etc:
[manager]
default-mysqld-path = /opt/mysql5/bin/mysqld
socket=/tmp/manager.sock
pid-file=/tmp/manager.pid
#password-file = /etc/mysqlmanager.passwd
monitoring-interval = 2
port = 1999
#bind-address = 192.168.1.5
[mysqld4]
socket=/tmp/mysql4.sock
mysqld-path=/opt/mysql4/bin/mysqld
port=3304
#mysqld=/opt/mysql4/bin/mysqld
datadir=/data/mysql4
language=/opt/mysql4/share/mysql/english
log=/opt/mysql4/mysql4.log
skip-locking
set-variable = key_buffer=16M
set-variable = max_allowed_packet=4M
set-variable = table_cache=64
set-variable = sort_buffer=512K
set-variable = net_buffer_length=8K
set-variable = myisam_sort_buffer_size=8M
set-variable = max_connections=300
set-variable = max_connect_errors=30
set-variable = wait_timeout=3600
#log-bin
server-id = 1
[mysqld5]
socket=/tmp/mysql5.sock
mysqld-path=/opt/mysql5/bin/mysqld
#mysqld=/opt/mysql5/bin/mysqld
default-table-type=innodb
default-storage-engine=innodb
port=3305
datadir=/data/mysql5
character-set-server=utf8
language=/opt/mysql5/share/mysql/english
log=/opt/mysql5/mysql5.log
server_id=1
skip-stack-trace
core-file
#skip-bdb
log-error
log=mylog
skip-locking
key_buffer = 384M
max_allowed_packet = 16M
max_connections = 350
table_cache = 512
sort_buffer_size = 2M
#net_buffer_length = 8K
#read_buffer_size = 256K
read_buffer_size = 2M
#read_rnd_buffer_size = 512K
#myisam_sort_buffer_size = 8M
myisam_sort_buffer_size = 64M
innodb_data_home_dir = /data/mysql5/
innodb_data_file_path = ibdata1:10M:autoextend
innodb_log_group_home_dir = /data/mysql5/
#innodb_log_arch_dir = /data/mysql5/data/
You can set …_buffer_pool_size up to 50 - 80 %
of RAM but beware of setting memory usage too high
innodb_buffer_pool_size = 16M
innodb_log_file_size = 5M
innodb_log_buffer_size = 8M
innodb_flush_log_at_trx_commit = 1
innodb_lock_wait_timeout = 50
Any ideas?