一、下载解压并打上内核补丁
我以2.6.10为例子，patche以bk4的例子，目的只是让大家知道怎么打patch，其实本人用的是2.6.6的内核，因为在AS3.0上升级到2.6.9以上的内核，mount大的nfs网络硬盘时，df 显示不正确，明明是800G的盘变成4.2G，不过还是能正常用，我升级过nfs和mount的包都没用，/var/log/message里提示是kernel: nfs warning: mount version older than kernel， 还望知道的告知一声，谢 :) BTW:2.6.8的内核没用过
内核源代码：
http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.10.tar.bz2 最新内核补丁：
http://www.kernel.org/pub/linux/kernel/v2.6/snapshots/patch-2.6.10-bk4.bz2 cd /usr/src
rm -rf linux
tar jxf /download/linux-2.6.10.tar.bz2
ln -s linux-2.6.10 linux
cd linux
bunzip2 -dv /download/patch-2.6.10-bk4.bz2 |patch -p1
如果在/usr/src目录下就用patch -p0
二、修改内核源代码 (升级2.6就是为了优化，干脆连源代码也改了吧)
1.修改/usr/src/linux/include/linux/posix_types.h
设置fd_set支持的最大数量
#define __FD_SETSIZE 1024 ---> 65536
2.修改/usr/src/linux/include/linux/fs.h
设置最大打开文件数量（TCP连接数量）
#define INR_OPEN 1024 ---> 65536
#define NR_FILE 8192 ---> 65536
#define NR_RESERVED_FILES 10 ---> 128
3.修改/usr/src/linux/include/net/tcp.h
设置TIMEOUT的时间为1秒
#define TCP_TIMEWAIT_LEN (60*HZ) 60 ---> 1*HZ
设置在backlog队列里的半连接的重试次数，每次都会花相应的时间，本质上也是减少重试时间
#define TCP_SYNACK_RETRIES 5 ---> 3
针对RHEL-AS3本来就是稳定+优化的，不过就算你用 RHEL-AS3 自己的内核，那也要修改一下上面的参数才好呀 :)
三、安装必要的工具
1.下载module-init-tools-3.1.tar.bz2
http://www.kernel.org/pub/linux/utils/kernel/module-init-tools/module-init-tools-3.1.tar.bz2
代码:
./configure --prefix=/
make moveold
make all install
./generate-modprobe.conf /etc/modprobe.conf
2.下载新的mkinitrd
ftp://195.220.108.108/linux/6/fedora/core/3/i386/os/Fedora/RPMS/mkinitrd-4.1.18-2.i386.rpm
它需要lvm2 device-mapper
ftp://195.220.108.108/linux/6/fedora/core/3/i386/os/Fedora/RPMS/device-mapper-1.00.19-2.i386.rpm
ftp://195.220.108.108/linux/6/fedora/core/3/i386/os/Fedora/RPMS/lvm2-2.00.25-1.01.i386.rpm
如果不更新这个包在make install时会提示以下错误：
代码:
No module mptbase found for kernel 2.6.10-bk4， aborting.
mkinitrd failed
make[1]: *** [install] Error 1
make: *** [install] Error 2
安装lvm2-2.00.25-1.01.i386.rpm时请用rpm -ivh --nodeps package name
四、make menuconfig
代码:
01.Code maturity level options --->
[*] Prompt for development and/or incomplete code/drivers
[*] Select only drivers expected to compile cleanly
02.General setup --->
[*] Support for paging of anonymous memory (swap)
[*] System V IPC
[*] POSIX Message Queues
[ ] BSD Process Accounting
[*] Sysctl support
[ ] Auditing support
[ ] Support for hot-pluggable devices
[*] Kernel Userspace Events
[ ] Kernel .config support
[*] Configure standard kernel features (for small systems) --->
[*] Load all symbols for debugging/kksymoops
[ ] Do an extra kallsyms pass
[*] Enable futex support
[*] Enable eventpoll support
[ ] Optimize for size
[*] Use full shmem filesystem
03.Loadable module support --->
[*] Enable loadable module support
[*] Module unloading
[ ] Forced module unloading
[ ] Module versioning support (EXPERIMENTAL)
[ ] Source checksum for all modules
[*] Automatic kernel module loading
04.Processor type and features --->
Subarchitecture Type (PC-compatible) --->
Processor family (Pentium-4/Celeron(P4-based)/Pentium-4 M/Xeon) --->
[*] Generic x86 support
[ ] HPET Timer Support
[*] Symmetric multi-processing support 多CPU
(8) Maximum number of CPUs (2-255)
[*] SMT (Hyperthreading) scheduler support
[*] Preemptible Kernel 抢占式内核，请选上它
[ ] Machine Check Exception
< > Toshiba Laptop support
< > Dell laptop support
< > /dev/cpu/microcode - Intel IA32 CPU microcode support
< > /dev/cpu/*/msr - Model-specific register support
< > /dev/cpu/*/cpuid - CPU information support
Firmware Drivers --->
High Memory Support (4GB) ---> 高内存
[ ] Allocate 3rd-level pagetables from highmem
[ ] Math emulation
[*] MTRR (Memory Type Range Register) support
[*] Enable kernel irq balancing
[ ] Use register arguments (EXPERIMENTAL)
05.Power management options (ACPI， APM) ---> 电源管理 自定 (偶没选)
06.Bus options (PCI， PCMCIA， EISA， MCA， ISA) ---> 板卡支持 自定
[*] PCI support
PCI access mode (Any) --->
[ ] Message Signaled Interrupts (MSI and MSI-X)
[*] Legacy /proc/pci interface
[*] PCI device name database
[ ] ISA support
[ ] MCA support
< > NatSemi SCx200 support
07.Executable file formats --->
[*] Kernel support for ELF binaries
<M> Kernel support for a.out and ECOFF binaries
<M> Kernel support for MISC binaries
08.Device Drivers ---> 设备驱动及网络支持
Generic Driver Options ---> 默认
[*] Select only drivers that don't need compile-time external firmware
[*] Prevent firmware from being built
Memory Technology Devices (MTD) ---> 不选
Parallel port support ---> 并行端口 自定(偶没选)
Plug and Play support ---> 支持热插拔 自定(偶没选)
Block devices --->
<*> Normal floppy disk support
< > Compaq SMART2 support
< > Compaq Smart Array 5xxx support
< > Mylex DAC960/DAC1100 PCI RAID Controller support
< > Micro Memory MM5415 Battery Backed RAM support (EXPERIMENTAL)
<M> Loopback device support
< > Cryptoloop Support
<M> Network block device support
< > Promise SATA SX8 support
<M> RAM disk support
(16) Default number of RAM disks
(4096) Default RAM disk size (kbytes)
() Source directory of cpio_list
[ ] Support for Large Block Devices
< > Packet writing on CD/DVD media
IO Schedulers ---> IO调度器，都选上吧 可以在grub.conf指定用IO调度哪种方式，后面会讲的
<*> Anticipatory I/O scheduler
<*> Deadline I/O scheduler
<*> CFQ I/O scheduler
ATA/ATAPI/MFM/RLL support ---> ATA设备 自定 (偶没选)
SCSI device support ---> SCSI设备 自定我有scsi的设备所以有以下选项
<*> SCSI device support
[*] legacy /proc/scsi/ support
--- SCSI support type (disk， tape， CD-ROM)
<*> SCSI disk support
因为偶式MPT的SCSI，所以以下都没选，省略之
Multi-device support (RAID and LVM) ---> 支持RAID和LVM(逻辑卷) 自定
[*] Multiple devices driver support (RAID and LVM)
<*> RAID support
< > Linear (append) mode
<*> RAID-0 (striping) mode
< > RAID-1 (mirroring) mode
< > RAID-10 (mirrored striping) mode (EXPERIMENTAL)
<*> RAID-4/RAID-5 mode
< > RAID-6 mode (EXPERIMENTAL)
<*> Multipath I/O support
< > Faulty test module for MD
<*> Device mapper support
< > Crypt target support
< > Snapshot target (EXPERIMENTAL)
< > Mirror target (EXPERIMENTAL)
< > Zero target (EXPERIMENTAL)
Fusion MPT device support ---> 偶的SCSI是这个，所以选了 还是自定
<*> Fusion MPT (base + ScsiHost) drivers
(40) Maximum number of scatter gather entries
<*> Fusion MPT misc device (ioctl) driver
IEEE 1394 (FireWire) support ---> 自定 (偶没选)
I2O device support ---> 自定 (偶没选)
Networking support ---> 网络选项
[*] Networking support
Networking options --->
<*> Packet socket
[ ] Packet socket: mmapped IO
< > Netlink device emulation
<*> Unix domain sockets 如果你有网络就选
< > PF_KEY sockets
[*] TCP/IP networking
[ ] IP: multicasting
[ ] IP: advanced router
[ ] IP: kernel level autoconfiguration
< > IP: tunneling
< > IP: GRE tunnels over IP
[ ] IP: ARP daemon support (EXPERIMENTAL)
[*] IP: TCP syncookie support (disabled per default) 能防DOS攻击，但会降低一点性能，总的说性价比不错
< > IP: AH transformation
< > IP: ESP transformation
< > IP: IPComp transformation
< > IP: tunnel transformation
<*> IP: TCP socket monitoring interface
IP: Virtual Server Configuration ---> lvs 支持
< > The IPv6 protocol (EXPERIMENTAL)
[*] Network packet filtering (replaces ipchains) ---> 包过滤省略(知道的自己选，不熟悉的都选上)
以下都没选，省略
[ ] Amateur Radio support --->
< > IrDA (infrared) subsystem support --->
< > Bluetooth subsystem support --->
[*] Network device support
< > Dummy net driver support 这个是nis服务器的吧，不大清楚，没用过
<*> Bonding driver support 双网卡绑定的
< > EQL (serial line load balancing) support
< > Universal TUN/TAP device driver support
ARCnet devices --->
Ethernet (10 or 100Mbit) --->
Ethernet (1000 Mbit) --->
< > Alteon AceNIC/3Com 3C985/NetGear GA620 Gigabit support
< > D-Link DL2000-based Gigabit Ethernet support
< > Intel(R) PRO/1000 Gigabit Ethernet support
< > National Semiconduct DP83820 support
< > Packet Engines Hamachi GNIC-II support
< > Packet Engines Yellowfin Gigabit-NIC support (EXPERIMENTAL)
< > Realtek 8169 gigabit ethernet support
< > Marvell Yukon Chipset / SysKonnect SK-98xx Support
<*> Broadcom Tigon3 support
以下都没选，省略
ISDN subsystem --->
Telephony Support --->
Input device support --->
Character devices --->
I2C support --->
Dallas's 1-wire bus --->
Misc devices --->
Multimedia devices --->
Graphics support --->
Sound --->
USB support --->
MMC/SD Card support ---> 以上都没选，需要的自己选
09.File systems ---> 文件系统
< > Second extended fs support
<*> Ext3 journalling file system support
[ ] Ext3 extended attributes
[*] JBD (ext3) debugging support
< > Reiserfs support
< > JFS filesystem support
< > XFS filesystem support
< > Minix fs support
< > ROM file system support
[ ] Quota support
< > Kernel automounter support
<*> Kernel automounter version 4 support (also supports v3)
CD-ROM/DVD Filesystems --->
<*> ISO 9660 CDROM file system support
[ ] Microsoft Joliet CDROM extensions
[ ] Transparent decompression extension
< > UDF file system support
DOS/FAT/NT Filesystems ---> floppy要用到的文件格式
<*> MSDOS fs support
<*> VFAT (Windows-95) fs support
(437) Default codepage for FAT (NEW)
(iso8859-1) Default iocharset for FAT (NEW)
< > NTFS file system support
Pseudo filesystems --->
[*] /proc file system support proc文件系统支持
[ ] /proc/kcore support
[ ] /dev file system support (OBSOLETE)
[ ] /dev/pts Extended Attributes
[*] Virtual memory file system support (former shm fs) 虚拟内存支持
[ ] tmpfs Extended Attributes
[ ] HugeTLB file system support
Miscellaneous filesystems --->
Network File Systems --->
<*> NFS file system support nfs客户端支持
[*] Provide NFSv3 client support
[ ] Provide NFSv4 client support (EXPERIMENTAL)
[ ] Allow direct I/O on NFS files (EXPERIMENTAL)
< > NFS server support nfs服务端支持
< > Secure RPC: Kerberos V mechanism (EXPERIMENTAL)
< > Secure RPC: SPKM3 mechanism (EXPERIMENTAL)
< > SMB file system support (to mount Windows shares etc.) samba支持
< > CIFS support (advanced network filesystem for Samba， Window and other CIFS compliant servers)
< > NCP file system support (to mount NetWare volumes)
< > Coda file system support (advanced network fs)
< > Andrew File System support (AFS) (Experimental)
Partition Types --->
Native Language Support ---> 自己选
10.Profiling support ---> 没选
11.Kernel hacking ---> 没选
12.Security options ---> 没选
13.Cryptographic options ---> 没选
14.Library routines --->
< > CRC-CCITT functions
<*> CRC32 functions
<M> CRC32c (Castagnoli， et al) Cyclic Redundancy-Check
五、编译安装
步骤:make -jn(n代表同时编译的进程，可以加快编译速度，n由你的配置决定，我的配置用15-25)
make modules_install
make install
六、grub的设置
设置之前先介绍一下2.6的I/O调度器
2.6包含的四个I/O调度器分别是No-op I/O scheduler、Anticipatory I/O scheduler、Deadline I/O scheduler与CFQ I/O scheduler。
在后文中分别简称为ns、as、ds与cfq。
ns是一个简化的调度程序它只作最基本的合并与排序。与桌面系统的关系不是很大，主要用在一些特殊的软件
与硬件环境下，这些软件与硬件一般都拥有自己的调度机制对内核支持的要求很小，这很适合一些嵌入式系统环境。作为桌面用户我们一般不会选择它。
as是当前内核中默认的I/O调度器。它拥有非常好的性能，在2.5中它就相当引人注意。在与2.4内核进行的对比测试中，在2.4中多项以分钟为单位
完成的任务，它则是以秒为单位来完成的。正因为如此它成为目前2.6测试版中默认的I/O调度器。但它也存在着弱点，它本身是比较庞大与复杂的，
在一些特殊的情况下，特别是在数据吞吐量非常大的数据库系统中它会变的比较缓慢。
ds就是针对as的缺点进行改善而来的，还处于测试阶段，但已经很稳定了。目前表现出的性能几乎与as一样好。加之比as更加小巧，
是相当有前途的调度器，值得一试：)
cfq为系统内的所有任务分配相同的带宽，提供一个公平的工作环境，它比较适合桌面环境。事实上在测试中它也有不错的表现，
mplayer xmms等多媒体播放器与它配合的相当好，回放平滑几乎没有因访问磁盘而出现的跳帧现象。对于喜欢在Linux下听音乐看电影的朋友不妨尝试一下。
好了，下面说说怎么设置：参数的格式为elevator=调度器名
修改/boot/grub/grub.conf，在kernel那行后门加入elevator=deadline
例如：kernel /boot/vmlinuz-2.6.10-bk4 ro root=/dev/你的根分区 elevator=deadline
七、reboot