Chattr
Name (Name) Chattr - Modify the unique attribute of the Linux Second Extension File System (E2FS) Synopsis (Total Overview) Chattr [-rv] [-V Version] [Mode] Files ... Description (Description) Chattr Modify File Unique attributes on Linux Second Expansion File System (E2FS)
Symbol mode has - = [asacdisu] several formats.
Ounger ` 'is used to add selected properties on the basis of file existing attributes;` -' is used to remove the selected properties on the file; and `= 'is used to specify the unique properties of the file.
Character `asacdisu 'options for file new properties: Do not update atime (a), synchronous update (S), can only be added (a), compressed (C), non-variable (i), non-transferable (D), delete Protection (S) and cannot be deleted (U). Options (option)
-R Recursively modifies the directory and the properties of the following. If you encounter a symbolic link in the recursive directory, the traversal will skip. -V Detailedly give the output information of Chattr and print the program version. -V version setting file The version of the system.
Attributes When modifying a file with the 'a' attribute, its ATIME record does not change. This can avoid some disk I / O processing in the laptop system.
Files of the `a 'attribute can only open in the Add mode to write. Only the super user can set or clear the property.
The file sets the `c 'attribute is automatically compressed by the kernel on the disk. Returns uncompressed data when reading from the file. A write to the file is saved before saving them to disk.
Files set the `d 'attribute cannot be backed up in the DUMP (8) program.
The file that sets the `I 'attribute cannot be modified: You can not delete it, you can't rename it, you can't create links to the file, and you can't write any data. Only super users can set or Clear this property.
When the file sets the `s' attribute is deleted, the data block is cleared and written back to the disk.
When modified a file setup `s 'attribute, the modification will be written synchronously on the disk; this has the same effect as the` Sync' mount option applied to the file subsystem.
When you delete a file setup `u 'attribute, it will be saved. This allows the user to request recovery of the deleted file.
Bugs and Limitations (BUGS and Limitations) For EXT2 FS 0.5a, `c 'and` u' attributes are not recognized by the kernel code. For Linux 2.0 kernel, 'A' attribute is not kernel code Supported. (NoAtime code is still tested.)
