/etc/sysctl.conf内核配置文件优化：

# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.

# Controls IP packet forwarding
net.ipv4.ip_forward = 0

# Controls source route verification
net.ipv4.conf.default.rp_filter = 1

# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0

# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0

# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1

# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 1

# Disable netfilter on bridges.
net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0

# Controls the maximum size of a message, in bytes
kernel.msgmnb = 65536

# Controls the default maxmimum size of a mesage queue
kernel.msgmax = 65536

# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736

# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296

# User Define
net.ipv4.tcp_fin_timeout = 1
net.ipv4.tcp_keepalive_time = 1200
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_synack_retries = 1
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_tw_recycle = 1
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.netdev_max_backlog = 262144
net.core.somaxconn = 262144
net.ipv4.tcp_max_orphans = 3276800
net.ipv4.tcp_max_syn_backlog = 262144
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608

关闭selinux，修改/etc/selinux/config：

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
# enforcing - SELinux security policy is enforced.
# permissive - SELinux prints warnings instead of enforcing.
# disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of these two values:
# targeted - Targeted processes are protected,
# mls - Multi Level Security protection.
SELINUXTYPE=targeted

系统最大打开文件数，修改/etc/security/limits.conf：

# /etc/security/limits.conf
#
#Each line describes a limit for a user in the form:
#
#<domain> <type> <item> <value>
#
#Where:
#<domain> can be:
# - an user name
# - a group name, with @group syntax
# - the wildcard *, for default entry
# - the wildcard %, can be also used with %group syntax,
# for maxlogin limit
#
#<type> can have the two values:
# - "soft" for enforcing the soft limits
# - "hard" for enforcing hard limits
#
#<item> can be one of the following:
# - core - limits the core file size (KB)
# - data - max data size (KB)
# - fsize - maximum filesize (KB)
# - memlock - max locked-in-memory address space (KB)
# - nofile - max number of open files
# - rss - max resident set size (KB)
# - stack - max stack size (KB)
# - cpu - max CPU time (MIN)
# - nproc - max number of processes
# - as - address space limit (KB)
# - maxlogins - max number of logins for this user
# - maxsyslogins - max number of logins on the system
# - priority - the priority to run user process with
# - locks - max number of file locks the user can hold
# - sigpending - max number of pending signals
# - msgqueue - max memory used by POSIX message queues (bytes)
# - nice - max nice priority allowed to raise to values: [-20, 19]
# - rtprio - max realtime priority
#
#<domain> <type> <item> <value>
#

#* soft core 0
#* hard rss 10000
#@student hard nproc 20
#@faculty soft nproc 20
#@faculty hard nproc 50
#ftp hard nproc 0
#@student - maxlogins 4
* soft nofile 65535
* hard nofile 65535
# End of file

在硬件系统上安装Linux系统之前，需要考虑许多有助于优化操作系统以及日后在其运行的应用程序的性能问题。这些问题包括：

• 选择分区位置
• 使用多个硬盘驱动器
• 选择文件系统

Linux至少需要一个root分区和一个swap分区，这两个分区以及其他需要频繁访问的分区在磁盘上的安装位置最终会影响到系统的性能。

• 对于var、swap、/var、/usr和/home等分区，都分别使用单独的分区
• 大多数硬盘驱动器的盘片在外侧磁道上封装的扇区要多于内侧磁道，因此从外侧磁道上读取数据要快得多。通常将编号较低的分区安装到外部磁道上（例如，/dev/hda1比/dev/hda3更接近与硬盘驱动器的外侧边缘），因此首先要放置需要经常访问的分区
• 第一个分区应该是swap分区（用于优化内存交换操作）
• 第二个分区应该是/var，因为日志记录会频繁地写入/var/log中
• 下一个分区应该是/usr，因为基本的系统工具和命令都位于/usr中
• root和/home分区可以驻留在靠近硬盘驱动器末尾的位置

使用多个硬盘驱动器，并要充分利用多个硬盘驱动器。

• 将经常访问的分区安装到更快的硬盘驱动器上
• 如果这些硬盘驱动器的性能相近，那么将常用的分区分别安装在不同的硬盘驱动器上。例如，讲/var和/usr分区分别置于两个不同的硬盘驱动器上，而交换分区位于自己单独的硬盘驱动器上
• 为了最大话总线吞吐率，应该将每个充当主设备的硬盘驱动器安放到I/O通道上。硬盘驱动器在不同I/O通道之间移动后，其设备名称会发生变化，因此需要对文件系统表（/etc/fstab）进行相应改动。如果对包含root或/boot分区的硬盘驱动器进行移动，那么还需要编辑/boot/grub/menu.lst文件

文件系统类型

• ext4，ext3的改进版，提供更加的性能和可靠性，更为丰富的功能
• ReiserFS，对于小型文件具有更佳的性能
• XFS，针对大型文件具有更佳的性能