Why should I care about SACL information?
Normally the /x
option is used because you want to preserve the security settings between the source and target file.
Note:
/x
: Copies file audit settings and system access control list (SACL) information (implies /o).
/o
: Copies file ownership and discretionary access control list (DACL) information.
So if you specify /x
you will preserve file audit settings, SACLs, file ownership and DACLs.
As you want to do the copy for backup, and may wish to restore later, you want to preserve all of these settings.
If you don't do this then the following may happen:
When you copy or move files and folders by using Windows Explorer, the permissions that are set on the files or folders may change. For example, when you copy a file in an NTFS file system volume or between two NTFS volumes, Windows treats it as a new file. As a new file, it takes on the permissions of the destination folder, and you become the CREATOR OWNER.
...
When you use the Xcopy command with the /O /X /E /H /K switches to
copy the files, the following inherited permissions apply:
- The security settings that are directly assigned to the files and folders are retained.
- The security settings that are inherited from the source parent folder are lost.
- The security settings of the destination folders are inherited.
- When you move files or folders to FAT volumes, the folders and files lose their NTFS permissions because FAT volumes do not support
NTFS permissions.
Source HOW TO: Copy a Folder to Another Folder and Retain its Permissions
Further Reading