Change GID on files?

When editing a group, if the group ID is changed then files owned by that group will remain owned by the old GID. This option can be used to update the ownership on files to the new GID by searching either the home directories of all users who are members of this group (Home Directories) or the entire filesystem (All Files). The All Files option may take a long time, especially if you have many large or NFS mounted filesystems.

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