磁盘寻道是一个巨大的性能瓶颈。当数据量开始增长到以致于有效缓存变得不可能时，这个问题会变得更加明显。对于大数据库，如果你以或多或少随机的方式访问数据，你可以确定读取至少需要一次磁盘寻道，写入则需要几次磁盘寻道。为了最小化这个问题，使用寻道时间低的磁盘。Disk seeks are a huge performance bottleneck. This problem becomes more apparent when the amount of data starts to grow so large that effective caching becomes impossible. For large databases where you access data more or less randomly, you can be sure that you need at least one disk seek to read and a couple of disk seeks to write things. To minimize this problem, use disks with low seek times.

通过符号链接文件到不同的磁盘或将磁盘进行条带化来增加可用磁盘轴数（从而减少寻道开销）：Increase the number of available disk spindles (and thereby reduce the seek overhead) by either symlinking files to different disks or striping the disks:

为了可靠性，你可能想使用 RAID 0 1（条带化加镜像），但在这种情况下，你需要 2 × N 个硬盘来存储 N 个硬盘的数据。如果你有足够的预算，这可能是最好的选择。不过，你也可能需要投资一些卷管理软件来有效地处理它。For reliability, you may want to use RAID 0+1 (striping plus mirroring), but in this case, you need 2 × N drives to hold N drives of data. This is probably the best option if you have the money for it. However, you may also have to invest in some volume-management software to handle it efficiently.

一个不错的选择是根据数据的重要性来改变 RAID 级别。例如，将可以重新生成的半重要数据存储在 RAID 0 磁盘上，但将真正重要的数据，如主机信息和日志，存储在 RAID 0 1 或 RAID N磁盘上。如果写入量很大，RAID N可能会成为问题，因为更新奇偶校验位需要时间。A good option is to vary the RAID level according to how critical a type of data is. For example, store semi-important data that can be regenerated on a RAID 0 disk, but store really important data such as host information and logs on a RAID 0+1 or RAID N disk. RAID N can be a problem if you have many writes, due to the time required to update the parity bits.

您还可以设置数据库使用的文件系统的参数：You can also set the parameters for the file system that the database uses:

如果你不需要知道文件的最后访问时间（这在数据库服务器上其实并不太有用），你可以使用 -o noatime 选项来挂载文件系统。这会跳过文件系统 inode 上最后访问时间的更新，从而避免一些磁盘寻道。If you do not need to know when files were last accessed (which is not really useful on a database server), you can mount your file systems with the -o noatime option. That skips updates to the last access time in inodes on the file system, which avoids some disk seeks.

在许多操作系统上，你可以通过使用 -o async 选项挂载文件系统，使其异步更新。如果你的计算机相对稳定，这应该能在不牺牲过多可靠性的情况下提高性能。（在 Linux 上这个选项默认是开启的。）On many operating systems, you can set a file system to be updated asynchronously by mounting it with the -o async option. If your computer is reasonably stable, this should give you better performance without sacrificing too much reliability. (This flag is on by default on Linux.)