> I'm trying to use tramp but it's very slow even I work with a local
> file owned by root.
Quoting from the Tramp manual, "Frequently Asked Questions":
• How could I speed up TRAMP?
In the backstage, TRAMP needs a lot of operations on the remote
host. The time for transferring data from and to the remote host
as well as the time needed to perform the operations there count.
In order to speed up TRAMP, one could either try to avoid some of
the operations, or one could try to improve their performance.
Use an external method, like ‘scp’.
Use caching. This is already enabled by default. Information
about the remote host as well as the remote files are cached for
reuse. The information about remote hosts is kept in the file
specified in ‘tramp-persistency-file-name’. Keep this file. If
you are confident that files on remote hosts are not changed out of
Emacs’ control, set ‘remote-file-name-inhibit-cache’ to ‘nil’. Set
also ‘tramp-completion-reread-directory-timeout’ to ‘nil’, *note
File name completion::.
Disable version control. If you access remote files which are not
under version control, a lot of check operations can be avoided by
disabling VC. This can be achieved by