注：部分图片因为质量较高，所以可能访问比较慢，请耐心等待。

Attention: Some pictures have high quality. So it may be slower when you visit the website, please be patient.

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它是一个分布式的内存缓存系统，Facebook(包含其他很多网站)用它作为Web服务器和MySQL服务器之间的缓存层(因为数据库访问相对比较慢)。

It's a distributed memory caching system which Facebook (and a ton of other sites) use as a caching layer between the web servers and MySQL servers (since database access is relatively slow).

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如果磁盘在大小或速度方面有差异，可以通过设置卷尽可能利用磁盘的特性，比如把不经常访问的数据放在比较慢的物理磁盘上。

If the disks vary in size or speed, you can place volumes to take best advantage of the disks' characteristics, such as putting seldom-accessed data on a slower physical disk.

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