<< So, by turning ctime checking off you will "only" lose the changed permissions, uid/gid of a file. It's up to the user to decide how comfortable they are with that setup. >>

Does this apply to CIFS permissions as well as unix permissions? Or does changing CIFS permissions change the mtime? (btw, for us windoze folks, could someone explain what mtime and ctime are?)

Thanks, MD

-----Original Message----- From: Stephen Manley [mailto:stephen@netapp.com] Sent: Wednesday, January 31, 2001 11:44 AM To: scl@sasha.acc.virginia.edu Cc: toasters@mathworks.com Subject: Re: Virus scans on NetApps and backups

8. Netapp's NDMP dump has an option to ignore ctime. I don't think this is a good idea because this causes dump to skip files that really should be dumped. If you rename a file, change its owner/group, or change its permissions, you probably want that change reflected in a dump. But these operations only trip ctime, not mtime. Also, if you read files from a tar or zip archive, the old mtimes are preserved, so dump may skip these files.

Steve -- One quick note. Starting in the 6.0 version of Ontap, incremental dumps will detect when new files are added to a tree and back those up as well -- even if the mtime is set back to an old date.

Furthermore, renaming a file actually changes the directory. You have to remove an entry and add an entry. This changes the mtime on the directory (or directories if you move from one dir to another). Thus, dump has always captured the changed names.

So, by turning ctime checking off you will "only" lose the changed permissions, uid/gid of a file. It's up to the user to decide how comfortable they are with that setup.

Stephen Manley DAM and NDMP Groundhog

P.S. As an example of what I mean by the renames, check out the examples below

cherryhill:/u/stephen/foobar(22) ls -lm total 8 drwxrwxr-x 2 stephen 4096 Jan 31 08:35 testdir drwxrwxr-x 2 stephen 4096 Jan 31 08:35 testdir2 cherryhill:/u/stephen/foobar(23) ls -lm testdir total 0 -rw-rw-r-- 1 stephen 0 Jan 31 08:35 old_name cherryhill:/u/stephen/foobar(24) mv testdir/old_name testdir2/new_name cherryhill:/u/stephen/foobar(25) ls -lm total 8 drwxrwxr-x 2 stephen 4096 Jan 31 08:37 testdir drwxrwxr-x 2 stephen 4096 Jan 31 08:37 testdir2 cherryhill:/u/stephen/foobar(26) ls -lm testdir2/ total 0 -rw-rw-r-- 1 stephen 0 Jan 31 08:35 new_name

As you can see - the file mtime hasn't changed, but the DIRECTORIES' mtimes HAVE changed. Thus, dump will capture the remove from testdir and the add to testdir2

cherryhill:/u/stephen/foobar(27) mv testdir2/new_name testdir2/really_new_name cherryhill:/u/stephen/foobar(28) ls -lm total 8 drwxrwxr-x 2 stephen 4096 Jan 31 08:37 testdir drwxrwxr-x 2 stephen 4096 Jan 31 08:39 testdir2 cherryhill:/u/stephen/foobar(29) ls -lm testdir2/ total 0 -rw-rw-r-- 1 stephen 0 Jan 31 08:35 really_new_name

Once again, by renaming the file within the directory, the file's mtime stays unchanged, but the DIRECTORY'S mtime is updated.