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The UMASK option specifies the file mode creation mask. It affects the file permission bits of newly created files and directories.
UMASK applies only to the HFS file system.
The permission mode of newly created files on HFS file systems is determined by either the source file permission mode (when the source file is from an HFS file system and source UDM component version is 3.2 or greater) or the UMASK option. The permission mode of newly created directories is always based upon the UMASK option.
When the file permission mode is not obtained from the source file, newly created files are created with a permission mode of 666, which is read-write permission for the owner, group, and other categories. All directories are created with a permission mode of 777, which is read-write-execute permission for owner, group, and other categories. UDM uses UMASK to turn off selected permission bits by subtracting the value of UMASK from the file mode 666 or directory mode 777.
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