Re: [rdiff-backup-users] Safe to compare by ctime?

[Dave Steinberg]

> 
> Hi all, I'm wondering how safe it would be to determine whether
> anything about a file has changed simply by looking at its ctime (plus
> probably some sanity checks, like the file type).
> 
> Earlier versions did not have this choice, because ctime's usually
> cannot be set, so there was no way to record the ctime of the source
> files on the destination side.  But now rdiff-backup by default stores
> the metadata on the destination side, and can record ctime.  I notice
> too that, at least under linux, updating a file's extended attributes
> or acls also changes its ctime.
> 
> So is ctime a good way to tell if something about a file has changed,
> or are there some reasons not to use it on some systems?

Ben, on my OpenBSD machines, the behavior is consistent with what you saw on
Linux.  Not having a reference handy, I wonder if that¹s a POSIX
requirement?

-- 
Dave Steinberg
http://www.geekisp.com