RedHat--FHS说明.docxVIP

5.2.?Overview of File System Hierarchy Standard (FHS)Red Hat Enterprise Linux uses the Filesystem Hierarchy Standard (FHS) file system structure, which defines the names, locations, and permissions for many file types and directories. The FHS document is the authoritative reference to any FHS-compliant file system, but the standard leaves many areas undefined or extensible. This section is an overview of the standard and a description of the parts of the file system not covered by the standard. The two most important elements of FHS compliance are: Compatibility with other FHS-compliant systems The ability to mount a /usr/ partition as read-only. This is especially crucial, since /usr/ contains common executables and should not be changed by users. In addition, since /usr/ is mounted as read-only, it should be mountable from the CD-ROM drive or from another machine via a read-only NFS mount. 5.2.1.?FHS OrganizationThe directories and files noted here are a small subset of those specified by the FHS document. Refer to the latest FHS document for the most complete information at /fhs/. .?Gathering File System InformationThe df command reports the systems disk space usage. Its output looks similar to the following: Filesystem 1K-blocks Used Available Use% Mounted on/dev/mapper/VolGroup00-LogVol00 6272120 4810348 57% / /dev/sda1 100691 9281 86211 10% /bootnone 322856 0 322856 0% /dev/shmBy default, df shows the partition size in 1 kilobyte blocks and the amount of used/available disk space in kilobytes. To view the information in megabytes and gigabytes, use the command df -h. The -h argument stands for human-readable format. The output for df -h looks similar to the following: Filesystem Size Used Avail Use% Mounted on/dev/mapper/VolGroup00-LogVol00 12G 6.0G 4.6G 57% / /dev/sda199M 9.1M 85M 10% /boot none 316M 0 31