/boot (100MB)
 boot 分区用来存放 Linux 内核，100MB 足够了。
 
/ (5GB)
 root 分区用来存放系统主要文件、程序等。CentOS/RHEL 5 最小安装需要 3GB，全安装（安装所有包）需要 5GB，所以给 5GB 应该够了。
 
/var (5GB)
 var 分区通常包括一些日志、临时文件、运行时目录等，推荐 3GB 以上，5GB 应该够了。
 
/home
 home 分区包含所有用户的数据，需要最多的硬盘空间，剩下的空间都分给它。
 
swap
 上个世纪的时候，看过的几乎所有 Linux 系统管理的书上都推荐设置交换分区大小为内存的2倍。这些建议到了现在就是那么适用了，现在的服务器动不动就是 16GB/32GB 内存，难道相应的交换分区也要扩大到 32GB/64GB？根据 OpenBSD 的安装建议：
 

Many people follow an old rule of thumb that your swap partition should be twice the size of your main system RAM. This rule is nonsense. On a modern system, that’s a LOT of swap, most people prefer that their systems never swap. You don’t want your system to ever run out of RAM+swap, but you usually would rather have enough RAM in the system so it doesn’t need to swap. If you are using a flash device for disk, you probably want no swap partition at all. Use what is appropriate for your needs.
 
再看看 RHEL 5 推荐的 swap 分区大小：