vim /etc/my.cnf

# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html

[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M

datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
event_scheduler=1
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER
max_connections=1000

skip_name_resolve

innodb_buffer_pool_size = 32000M
innodb_log_file_size = 2048M

query_cache_type=0
query_cache_size=0
query_cache_limit=1M

server-id = 112031
master-info-repository = table
relay-log-info-repository = table
relay-log-recovery=1

log-bin = mysql-bin
expire_logs_days = 7
binlog_format = mixed
#binlog-ignore-db = mysql
binlog-ignore-db = sys
binlog-ignore-db = phpmyadmin
binlog-ignore-db = information_schema
binlog-ignore-db = performance_schema

log-slave-updates
#replicate-ignore-db = mysql
#
slave-skip-errors=all

slow_query_log = 1
long_query_time = 2
#log_output = table

五类线的标识是“CAT5”，超五类线的标识是“CAT5E”，六类线的标识是“ CAT6”。

超五类双绞线裸铜线径为0.51mm（线规为24AWG），绝缘线径为0.92mm，UTP电缆直径为5mm；

六类非屏蔽双绞线裸铜线径为0.57mm（线规为23AWG），绝缘线径为1.02mm，UTP电缆直径为6.53mm。

T568B：橙白、橙、绿白、蓝、蓝白、绿、棕白、棕    

T568A：绿白、绿、橙白、蓝、蓝白、橙、棕白、棕

T568Q：绿白、绿、橙白、棕白、棕、橙、蓝、蓝白

测试写速度：

time dd if=/dev/zero of=/tmp/test bs=8k count=1000000

测试读速度：

time dd if=/tmp/test of=/dev/null bs=8k

测试读写速度：

time dd if=/tmp/test of=/tmp/test1 bs=64k

一行命令让CPU占用率达到100％

for i in `seq 1 $(cat /proc/cpuinfo |grep "physical id" |wc -l)`; do dd if=/dev/zero of=/dev/null & done

CREATE PROCEDURE curdemo()
BEGIN
  DECLARE done INT DEFAULT 0;
  DECLARE a CHAR(16);
  DECLARE b,c INT;
  DECLARE cur1 CURSOR FOR SELECT id,data FROM test.t1;
  DECLARE cur2 CURSOR FOR SELECT i FROM test.t2;
  DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done = 1;
  
  OPEN cur1;
  OPEN cur2;
  
  REPEAT
    FETCH cur1 INTO a, b;
    FETCH cur2 INTO c;
    IF NOT done THEN
       IF b < c THEN
          INSERT INTO test.t3 VALUES (a,b);
       ELSE
          INSERT INTO test.t3 VALUES (a,c);
       END IF;
    END IF;
  UNTIL done END REPEAT;
  
  CLOSE cur1;
  CLOSE cur2;
END

vmware -vl
esxcli software vib list

esxcli software vib install -d "/vmfs/volumes/datestroe02/os/ESXi670-202207001.zip"

esxcli software sources profile list -d /vmfs/volumes/iso/VMware-ESXi-8.0-20513097-depot.zip
esxcli software profile update -d /vmfs/volumes/iso/VMware-ESXi-8.0-20513097-depot.zip -p ESXi-8.0.0-20513097-standard

vmkfstools -z /vmfs/devices/disks/naa.50000396a1b811a9  /vmfs/volumes/5eefaf52-4d40184a-07a6-4cd98f75a46c/nas1-1T.vmdk

安装命令

yum install certbot

获取证书命令

certbot certonly --manual -m jason@zhisg.com -d *.zhisg.com
certbot certonly --webroot -w /var/www/html/zhisg/ -d www.zhisg.com

certbot renew   #继订全部证书
certbot renew --cert-name domain.com  #指定证书

certbot certificates                                         # 列出当前系统上所有由 Certbot 管理的证书
certbot delete --cert-name domain.com       # 删除指定的证书及其配置

certonly 表示安装模式，Certbot 有安装模式和验证模式两种类型的插件。
–manual 表示手动安装插件，Certbot 有很多插件，不同的插件都可以申请证书，用户可以根据需要自行选择
-d 为那些主机申请证书，如果是通配符，输入 *.domain.com （替换为你自己的域名）
–preferred-challenges dns，使用 DNS 方式校验域名所有权
–server，Let’s Encrypt ACME v2 版本使用的服务器不同于 v1 版本，需要显示指定。

编辑配置文件：/etc/httpd/conf.modules.d/00-mpm.conf

LoadModule mpm_event_module modules/mod_mpm_event.so

<IfModule mpm_event_module>
    StartServers             4
    MinSpareThreads         16
    MaxSpareThreads        512
    ThreadsPerChild         64
    ServerLimit             64
    MaxRequestWorkers     4096
    MaxConnectionsPerChild 15000
</IfModule>

WordPress 打开很慢，检查下是不是有调用google的JS或CSS，搜“googleapis.com”，改到其它的共公库，或是本地的库就OK了。