Understand Oracle Validated Configurations
Oracle Validated Configurations致力于为企业提供更简易、更快捷、成本更低的基于Linux和Oracle VM的解决方案。该计划向我们提供经过测试和验证的体系架构，其附带的文档揭示了相关硬件、软件、存储、网络原件的最佳配置实践，以帮助系统提升性能和可收缩性并降低成本。从行业角度来说Oracle Validated Configurations所验证的配置及提供的最佳实践文档受到Oracle合作伙伴的接受和认可，Oracle Validated Configurations提供了推荐使用的软硬件组合的部署方案细节，这些方案已被证明是十分有益的。
Oracle Validated Configurations提供了那些好处？
Oracle Validated Configurations是对系统底层组件在高负载下良好工作的有力保证，同时这些推荐配置也在实践中被证明是易于快速部署的。其有助于：
- 实现标准化的、具有可扩展性、高可用的且成本低廉的解决方案
- 加速并简化在Linux上部署Oracle软件
- 为最终用户降低了测试系统所要花费的昂贵成本
- 转嫁了用户的风险
那么Oracle Validated Configurations和最早推出的Oracle Product Certification有什么区别？
传统的Oracle Product Certification在认证某个操作系统平台后，可以确认Oracle的相关产品完全支持该系统平台。而Oracle Validated Configurations则通过测试验证更进一步提供了完整的组件组合信息，这些信息包括针对软硬件、存储的版本、设置、补丁的推荐值，而这些推荐值来源于Oracle及其合作伙伴的Linux测试实验室中高压测试的经验。
我们要如何使用Oracle Validated Configurations？
我们可以通过访问或订阅 <Browse Published Validated Configurations>来了解OVC中已经验证的软硬件组合配置。
此外在Oracle Enterprise Linux中提供了oracle-validated RPM软件包，通过使用OEL DVD介质上的该包我们可以更简单地部署安装Oracle产品所需要的软件包环境，特别是对于Oracle Database的安装来说有了以上特性后显得特别简单。
通过安装DVD介质使用oracle-validate软件包的步骤如下:
1.创建介质装载目录/media/disk: mkdir /media/disk
2.插入OEL DVD光盘
3.装载目录: mount /dev/cdrom /media/disk
4.touch /etc/yum.repos.d/public-yum-el5.repo，并加入以下内容
[oel5]
name = Enterprise Linux 5.5 DVD
baseurl=file:///media/disk/Server/
gpgcheck=0
enabled=1
注意以上name中的OEL版本(指5.5)可能和你手头DVD的版本不一样，这一般不会造成问题，但要保证当前操作系统与安装介质中的完全一致。
5.正式安装oracle-validated软件包环境，使用yum install oracle-validated 命令:
yum install oracle-validated
完成对oracle-validated的安装后操作系统软件包环境也就水道渠成了，此外该oracle-validated包还会帮助我们设置必要的Linux内核参数，具体来说它会修改/etc/sysctl.conf配置文件中的参数到Oracle推荐的值，以下为完成oracle-validated安装后的sysctl.conf，供参考:
# Kernel sysctl configuration file for Oracle Enterprise 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
# 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
# Controls the maximum size of a message, in bytes
# Controls the default maxmimum size of a mesage queue
# Controls the maximum shared segment size, in bytes
# Controls the maximum number of shared memory segments, in pages
# For 11g, Oracle-Validated setting for fs.file-max is 6815744
# For 10g, uncomment 'fs.file-max = 327679', and comment 'fs.file-max = 6553600' entry and re-run sysctl -p
# fs.file-max = 327679
fs.file-max = 6815744
# Oracle-Validated setting for kernel.msgmni is 2878
kernel.msgmni = 2878
# Oracle-Validated setting for kernel.msgmax is 8192
kernel.msgmax = 8192
# Oracle-Validated setting for kernel.msgmnb is 65536
kernel.msgmnb = 65536
# Oracle-Validated setting for kernel.sem is '250 32000 100 142'
kernel.sem = 250 32000 100 142
# Oracle-Validated setting for kernel.shmmni is 4096
kernel.shmmni = 4096
# Oracle-Validated setting for kernel.shmall is 1073741824
kernel.shmall = 1073741824
# Oracle-Validated setting for kernel.shmmax is 4398046511104 on x86_64 and 4294967295 on i386 architecture. Refer Note id 567506.1
kernel.shmmax = 4398046511104
# Oracle-Validated setting for kernel.sysrq is 1
kernel.sysrq = 1
# Oracle-Validated setting for net.core.rmem_default is 262144
net.core.rmem_default = 262144
# For 11g, Oracle-Validated setting for net.core.rmem_max is 4194304
# For 10g, uncomment 'net.core.rmem_max = 2097152', comment 'net.core.rmem_max = 4194304' entry and re-run sysctl -p
# net.core.rmem_max = 2097152
net.core.rmem_max = 4194304
# Oracle-Validated setting for net.core.wmem_default is 262144
net.core.wmem_default = 262144
# For 11g, Oracle-Validated setting for net.core.wmem_max is 1048576
# For 10g, uncomment 'net.core.wmem_max = 262144', comment 'net.core.wmem_max = 1048576' entry for this parameter and re-run sysctl -p
# net.core.wmem_max = 262144
net.core.wmem_max = 1048576
# Oracle-Validated setting for fs.aio-max-nr is 3145728
fs.aio-max-nr = 3145728
# For 11g, Oracle-Validated setting for net.ipv4.ip_local_port_range is 9000 65500
# For 10g, uncomment 'net.ipv4.ip_local_port_range = 1024 65000', comment 'net.ipv4.ip_local_port_range = 9000 65500' entry and re-run sysctl -p
# net.ipv4.ip_local_port_range = 1024 65000
net.ipv4.ip_local_port_range = 9000 65500
# Oracle-Validated setting for vm.min_free_kbytes is 51200 to avoid OOM killer
vm.min_free_kbytes = 51200
oracle-validated包还会帮助我们修改/etc/security/limits.conf配置以获得合理的shell limit:
[oracle@rh2 ~]$ ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 31668
max locked memory (kbytes, -l) 50000000
max memory size (kbytes, -m) unlimited
open files (-n) 131072
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 131072
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
[oracle@rh2 ~]$ cat /etc/security/limits.conf
# Oracle-Validated setting for nofile soft limit is 131072
oracle soft nofile 131072
# Oracle-Validated setting for nofile hard limit is 131072
oracle hard nofile 131072
# Oracle-Validated setting for nproc soft limit is 131072
oracle soft nproc 131072
# Oracle-Validated setting for nproc hard limit is 131072
oracle hard nproc 131072
# Oracle-Validated setting for core soft limit is unlimited
oracle soft core unlimited
# Oracle-Validated setting for core hard limit is unlimited
oracle hard core unlimited
# Oracle-Validated setting for memlock soft limit is 50000000
oracle soft memlock 50000000
# Oracle-Validated setting for memlock hard limit is 50000000
oracle hard memlock 50000000
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