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20.5. Archiving File Systems With ACLs

By default, the dump command now preserves ACLs during a backup operation. When archiving a file or file system with tar, use the --acls option to preserve ACLs. Similarly, when using cp to copy files with ACLs, include the --preserve=mode option to ensure that ACLs are copied across too. In addition, the -a option (equivalent to -dR --preserve=all) of cp also preserves ACLs during a backup along with other information such as timestamps, SELinux contexts, and the like. For more information about dump, tar, or cp, refer to their respective man pages.
The star utility is similar to the tar utility in that it can be used to generate archives of files; however, some of its options are different. Refer to 表 20.1 “Command Line Options for star” for a listing of more commonly used options. For all available options, refer to man star. The star package is required to use this utility.

表 20.1. Command Line Options for star

Option Description
-c Creates an archive file.
-n Do not extract the files; use in conjunction with -x to show what extracting the files does.
-r Replaces files in the archive. The files are written to the end of the archive file, replacing any files with the same path and file name.
-t Displays the contents of the archive file.
-u Updates the archive file. The files are written to the end of the archive provided the following are true:
  • They do not already exist in the archive.
  • The files to be updated are newer than the files of the same name already in the archive.
This option only works if the archive is a file or an unblocked tape which can go in reverse (as opposed to only going back to 0).
-x Extracts the files from the archive. If used with -U and a file in the archive is older than the corresponding file on the file system, the file is not extracted.
-help Displays the most important options.
-xhelp Displays the least important options.
-/ Do not strip leading slashes from file names when extracting the files from an archive. By default, they are stripped when files are extracted.
-acl When creating or extracting, archives or restores any ACLs associated with the files and directories.