One of the most important aspects of an operating system is the Virtual Memory Management system. Virtual Memory (VM) allows an operating system to perform many of its advanced functions, such as process isolation, file caching, and swapping. As such, it is imperative that an administrator understand the functions and tunable parameters of an operating system's Virtual Memory Manager so that optimal performance for a given workload may be achieved. After reading this article, the reader should have a rudimentary understanding of the data the Red Hat Enterprise Linux (RHEL3) VM controls and the algorithms it uses. Further, the reader should have a fairly good understanding of general Linux VM tuning techniques. It is important to note that Linux as an operating system has a proud legacy of overhaul. Items which no longer serve useful purposes or which have better implementations as technology advances are phased out. This implies that the tuning parameters described in this article may be out of date if you are using a newer or older kernel. Fear not however! With a well grounded understanding of the general mechanics of a VM, it is fairly easy to convert knowledge of VM tuning to another VM. The same general principles apply, and documentation for a given kernel (including its specific tunable parameters) can be found in the corresponding kernel source tree under the file Documentation/sysctl/vm.txt.
本日志由 flyinweb 于 2009-12-08 17:51:10 发表到 Linux 中,目前已经被浏览 3637 次,评论 0 次;
作者添加了以下标签: Virtual Memory,VM;
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原文作者: Peter Zaitsev
原文来源: http://www.mysqlperformanceblog.com/2006/05/17/mysql-server-memory-usage
译者:叶金荣(http://imysql.cn/node/97)
Every so often people ask me the question how should they estimate memory consumption by MySQL Server in given configuration. What is the formula they could use.
经常有人问我配置MySQL时该如何估算内存的消耗。那么该使用什么公式来计算呢?
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常见 iptables 的 firewall 设定配置问题
作者: 小州 (kenduest)
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一、标题列表项目: (一般本机的 firewall 配置问题)
1. 如何查询我目前 iptables 的配置组态设定 ?
2. 如何关闭 Linux Distro 本身的 firewall 配置并让规则清空不启用?
3. 关于 RedHat 9, Fedora 与 RHEL 的 firewall 配置问题
4. 如何使用手动方式清空与重置 iptables firewall rule?
5. iptables firewall 本身封包比对判断流程图为何?
6. iptables firewall 本身封包比对规则方式为何?
7. 使用 -P INPUT DROP 引起的主機本身對外連線不通问题?
8. 使用 -P INPUT DROP 导致本机存取自己服务也受到限制?
9. 使用 -P INPUT DROP 引起的网路存取正常,但是 ftp 连入却失败?
10. 使用 -P OUTPUT DROP 引起的网路不通问题?
11. 有无建议本机 firewall 服务只有开放对外项目,其余禁止的配置方式?
二、标题列表项目: (提供 NAT 服务配置问题)
1. 一般建议单纯化的 NAT 服务配置语法为何?
2. 透过 NAT 上网的内部 ip 主机,ftp 连结存取错误?
3. 如何配置连线到 NAT 主机某个对外 Port 时,可以转送到内部某主机?
4. 使用 -j MASQUERADE 与 -j SNAT 于 NAT 使用差异 ?
环境:
LAMP PHP(FastCGI )
症状:
[Tue Dec 01 10:19:21 2009] [notice] mod_fcgid: /var/www/vhosts/xiangbaozhongxin.com/httpdocs/shopadmin/index.php total process count 65 >= 64, skip the spawn request
[Tue Dec 01 10:19:21 2009] [notice] mod_fcgid: /var/www/vhosts/xiangbaozhongxin.com/httpdocs/shopadmin/index.php total process count 65 >= 64, skip the spawn request
解决办法:
查找mod_fcgid配置文件
- <IfModule mod_fcgid.c>
- AddHandler fcgid-script .fcgi
- IPCConnectTimeout 20
- MaxProcessCount 5
- DefaultMaxClassProcessCount 2
- DefaultMinClassProcessCount 1
- </IfModule>
增加MaxProcessCount 参数值
本日志由 flyinweb 于 2009-12-01 15:17:46 发表到 Linux 中,目前已经被浏览 3946 次,评论 0 次;
作者添加了以下标签: MaxProcessCount,fcgid;
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本日志由 flyinweb 于 2009-12-01 08:29:08 发表到 Linux 中,目前已经被浏览 6466 次,评论 0 次;
作者添加了以下标签: Kernel Upgrade,/dev/root,CONFIG_SYSFS_DEPRECATED_V2;
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It is quite useful and interesting too.
VIRT 的上限是64G,也就是36位, cat /proc/cpuinfo的结果是:addre
昨天要准备用线程重写webbench,试验了下Fedora Linux 2.6.35.14
不明白您的具体的意思是什么?
已经发送到你QQ邮箱
http://www.2mysite.net/scriptencoder/screnc.asp 站长你好,看
你好,我发现一个问题,就是从mysqld2同步过来的数据,在mysqld1的
晕,我说是怎么回事情,原来我和你一样,忘记设置了活动分区