Server Mgmt Performance Advanced

Server optimization for VPS and dedicated servers

Improve Linux server performance with swap configuration, web server tuning, PHP-FPM, MySQL optimization, and caching.

UnderHost NOC Network Operations

10 min read Updated June 2026

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Swap space
PHP-FPM tuning
MySQL optimization
Nginx optimizations
Caching layers

A freshly provisioned VPS often needs tuning to handle real traffic. These are practical, commonly-applied changes for Linux servers running a web stack. Apply changes one at a time and monitor the effect.

Swap space

Swap prevents out-of-memory crashes by using disk as overflow RAM. Slow but better than crashing. Add a 1 GB swap file on a VPS with 1–2 GB RAM:

fallocate -l 1G /swapfile
chmod 600 /swapfile
mkswap /swapfile
swapon /swapfile
echo '/swapfile none swap sw 0 0' | tee -a /etc/fstab

Set swappiness to a low value (use RAM first):

echo 'vm.swappiness=10' >> /etc/sysctl.conf
sysctl -p

PHP-FPM tuning

PHP-FPM runs PHP processes as a pool. Key pool settings in /etc/php/8.x/fpm/pool.d/www.conf:

pm = dynamic
pm.max_children = 10        ; Max simultaneous PHP processes
pm.start_servers = 2        ; Processes started on launch
pm.min_spare_servers = 1    ; Min idle processes
pm.max_spare_servers = 3    ; Max idle processes
pm.max_requests = 500       ; Restart process after N requests (prevents memory leaks)

Rule of thumb: max_children = available RAM / average PHP process size. Check average process size with ps aux | grep php.

MySQL optimization

Key settings in /etc/mysql/mysql.conf.d/mysqld.cnf for a 2 GB VPS:

innodb_buffer_pool_size = 512M   ; Main InnoDB cache-50-70% of available RAM
query_cache_type = 0             ; Disable query cache (deprecated in MySQL 8)
max_connections = 100            ; Limit connections to prevent overload
tmp_table_size = 64M
max_heap_table_size = 64M

Restart MySQL after changes: systemctl restart mysql

Nginx optimizations

In /etc/nginx/nginx.conf:

worker_processes auto;       ; Match CPU core count
worker_connections 1024;     ; Per-worker connections

gzip on;                     ; Enable gzip compression
gzip_types text/plain text/css application/json application/javascript text/xml;

client_max_body_size 64M;    ; Allow larger file uploads

keepalive_timeout 65;
sendfile on;
tcp_nopush on;

Caching layers

Cache type	Tool	Benefit
Opcode cache	OPcache (built into PHP)	Caches compiled PHP bytecode-major speedup for all PHP sites
Object cache	Redis or Memcached	Caches database query results-reduces MySQL load
Page cache	Nginx FastCGI cache or WordPress plugin	Serves pre-rendered HTML-eliminates PHP execution for cached pages