When inode change time changes?

[Artem Kuchin]

Oliver Fromme wrote:
> Artem Kuchin <matrix at itlegion.ru> wrote:
>> I use gtar (gtar because it has incremental
>> backups, and tar does not)
> 
> You _can_ use BSD tar for incremental backups.  I do that
> every day.

Yes, but that's not real incremental backup because
if you restore data you'll get a bunch of files that were
deleted along the way. gtar stores full file list and
actually deleted the deleted files when restoring.

And i have excessively many of such created and
deleted files and i need only current ones. So tar is
of no use for me.

Also, i use inode time because i only need files
which really have been changed. For example,
i you restore a file from a month ago it will have
a date which is a month ago. Then that backup
is destroyed but this file would not be backed up
because the date is too  much in the past. So, we
loose the file. If i used inode change time the file
will be backup in any case. However, some 
"stupid" programs like mysql or qmail seem to
touch files so, for example, all mail message and
databases are backed up every time. And this sucks.
So, when backing up these files i need to use file
modification time and it is suitable here, since these
file are never managed by human, only by daemon and
old file eather go away (like in email) or change its mod time
(like in mysql).

What is still do not understand is what time gtar  uses for
--newer option.

Man page says:

--newer date            Only store files with creation time newer than
                        date.

This is simply not true. NOT creation time defenetly. It is either 
modification time or inode change time. Which one?

--
Regards,
Artem