Linux 小記憶體主機優化(VPS) | 蝸牛總是想落跑

面對許多的VPS都是小記憶體的情況，大的記憶體VPS方案又非常的貴，先前有提過，怎麼在Linux下，增加SWAP交換式記憶體。

但是，再怎麼說，還是實體記憶體的速度會比交換式的記憶體來的快，在效能考量下，我們把記憶體最佳化處理，會得到最大的效能產出。

以亞馬遜EC2 Micro Instaces為例,還沒有優化之前的狀況，只剩下54MB左右的空間。

優化之後，只用掉145MB的空間，還有450MB左右的空間未使用，這時，mysql, web, webmin 等服務已經起來了，算是相當的給力。

要怎麼做呢？

首先，先做套件的更新與安裝
apt-get upgrade
apt-get dist-upgrade
apt-get autoclean
apt-get install perl gcc libnet-ssleay-perl openssl libauthen-pam-perl libpam-runtime libio-pty-perl apt-show-versions python

如果沒有裝資料庫的話，裝一下資料庫
apt-get install mysql-server mysql-client

mysql的記憶體優化，修改指令如下 vi /etc/mysql/my.cnf
[mysqld]
#
# * Basic Settings
#
user            = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
port            = 3306
basedir         = /usr
datadir         = /var/lib/mysql
tmpdir          = /tmp
language        = /usr/share/mysql/english
skip-external-locking
loose-skip-innodb

#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address            = 127.0.0.1
#
# * Fine Tuning
#
key_buffer              = 8M
max_allowed_packet      = 8M
thread_stack            = 192K
thread_cache_size       = 8
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched
myisam-recover         = BACKUP
#max_connections        = 100
#table_cache            = 64
#thread_concurrency     = 10
#
# * Query Cache Configuration
#
query_cache_limit       = 1M
query_cache_size        = 8M

記得，修改完設定檔之後，記得要存檔，並且重新啟動mysql
service mysql restart

而Web server我們不使用傳統的apache，在ubuntu上，apache2就算再怎麼優化，仍然很佔記憶體，所以我們也不用內建的apache+php5-cgi，我們使用lighttp+php5-cgi(可以用php5-fpm取代)

安裝lighttpd
apt-get install lighttpd

安裝php相關套件
apt-get install php5-cgi php5-common php5-curl php5-gd php5-suhosin php5-mysql

修改lighttpd的設定檔
使用fast-cgi做為php的解譯引擎
vi /etc/lighttpd/lighttpd.conf

server.modules = (
“mod_access”,
“mod_fastcgi”,
“mod_alias”,
“mod_compress”,
“mod_redirect”,
“mod_rewrite”,
“mod_accesslog”,
)

server.document-root        = “/var/www”
server.upload-dirs          = ( “/var/cache/lighttpd/uploads” )
server.errorlog             = “/var/log/lighttpd/error.log”
server.pid-file             = “/var/run/lighttpd.pid”
server.username             = “www-data”
server.groupname            = “www-data”

fastcgi.server = ( “.php” => ((
“bin-path” => “/usr/bin/php-cgi”,
“socket” => “/tmp/php.socket”,
“max-procs” => 1,
“bin-environment” => (
“PHP_FCGI_CHILDREN” => “3”,
“PHP_FCGI_MAX_REQUESTS” => “1000”
),
“bin-copy-environment” => (
“PATH”, “SHELL”, “USER”
),
“broken-scriptfilename” => “enable”
)))

別忘了，修改完設定檔要重啟lighttpd

sudo service php5-cgi stop
sudo service lighttpd restart

正常來說，就可以讀取到網頁資料
我使用了雅黑探針，截圖如下