SCSA10-1 Objective 2.6 - Check and resolve Solaris filesystem inconsistencies, fsck
Now that we have created filesystems, they need to be maintained and healthy. This objective covers checking, fixing, and monitoring Solaris filesystems:
Given a scenario, check and resolve Solaris 10 OS file system inconsistencies using fsck, and monitor file system usage using the command line (df, du, and quot commands).
The fsck command will, if you administer Solaris systems long enough, make you a hero. When fsck is run, it will check and try to repair these things (detailed knowledge of this is not required for the exam, but it is good to know its limitations). The basic usage of fsck is interactive mode in which fsck will present you with every error and ask if you what to do. This can be tedious, so an option for fsck automatically answers yes (to fix errors).
The df and du commands are handy tools for monitoring the disk usage of filesystems (df) or files/directories (du). Both of these commands accept the command line switch -k to present their output in kilobytes (instead of blocks) and Solaris 10 also accepts the -h switch to show the output in human readable formats (MB, GB, etc.).
The df command shows the “disk free” as well as disk used and total disk size of all mounted filesystems (default) or of the filesystems specified on the command line.
The du command takes one or more file or directory names on the command line and shows the disk usage of each file or directory and the directory’s files, subdirectories, and each subdirectory’s files/subdirectories. This listing can get out of hand quickly. The -s option provides a summary and is useful for directories. To determine the space in kilobytes used by a directory called ’stuff’ the command ‘du -ks stuff’ is all you need.
The quot command can be used to determine the amount of disk space used by different users on a filesystem. The command ‘quot /’ will show a summary of disk space (in blocks) for the root (/) filesystem for each user owning files in /, sorted by space used. The -a option can be used instead of specifying a filesystem and will make quot go through all of the mounted filesystems. You must be superuser to run quot.