debian 内核参数优化

以下是一些可以优化 Debian 内核的常见参数：

1. 提高 TCP/IP 性能：在 /etc/sysctl.conf 中添加以下参数：

   net.core.rmem_max = 16777216
   net.core.wmem_max = 16777216
   net.ipv4.tcp_rmem = 4096 87380 16777216
   net.ipv4.tcp_wmem = 4096 65536 16777216
   net.ipv4.tcp_fin_timeout = 15
   net.ipv4.tcp_slow_start_after_idle = 0
   net.ipv4.tcp_tw_reuse = 1
   

2. 提高文件系统性能：在 /etc/fstab 中添加以下参数：

   noatime,nodiratime,nobarrier
   

3. 禁用不必要的内核模块：在 /etc/modprobe.d/blacklist.conf 中添加以下模块：

   blacklist bluetooth
   blacklist firewire-core
   blacklist pcspkr
   

4. 提高性能：在 /etc/sysctl.conf 中添加以下参数：

   vm.swappiness = 0
   vm.dirty_ratio = 60
   vm.dirty_background_ratio = 2
   kernel.sched_migration_cost_ns = 5000000
   kernel.sched_autogroup_enabled = 0
   kernel.sched_min_granularity_ns = 10000000
   kernel.sched_wakeup_granularity_ns = 15000000
   kernel.sched_child_runs_first = 0
   

5. 提高网络性能：在 /etc/sysctl.conf 中添加以下参数：

   net.core.netdev_max_backlog = 250000
   net.core.somaxconn = 65535
   net.ipv4.ip_local_port_range = 1024 65535
   net.ipv4.tcp_max_syn_backlog = 8192
   net.ipv4.tcp_max_tw_buckets = 2000000
   net.ipv4.tcp_mem = 786432 1048576 26777216
   net.ipv4.tcp_syncookies = 1
   net.ipv4.tcp_timestamps = 1
   

6. 提高磁盘性能：在 /etc/sysctl.conf 中添加以下参数：

   vm.dirty_writeback_centisecs = 1500
   vm.dirty_expire_centisecs = 1500
   vm.dirty_background_bytes = 67108864
   vm.dirty_bytes = 134217728
   vm.dirty_writeback_suspend = 1
   ``