On Mar 26, 9:02am, Greg Freemyer wrote:
}
} I've been testing access times today. This is not related to an
} active case, just curiosity.
}
} I found that "robocopy /mir" and tar both modify the last access time.
} Also, on my Linux fileserver I use xfsdump to make my nightly backups
} and it modifies access times.
}
} I have not tested virus scanning or any other backup software yet.
}
} Does anyone know of a resource that describes what tools preserve access time.
I have no idea how xfsdump works; but, traditionally dump read the
raw disk (it understood the filesystem format) and as such wouldn't
modify access times. However, with modern journalling and log
structured filesystems (I believe XFS is a journalling filesystem),
which have a tendency to move things around, this might not be a
reasonable thing to do anymore. Without reading the raw disk it would
be difficult not to mess with the timestamps. One could stat(2) the
file before reading it and then use utimes(2) to fix the access time
afterwards. However, this would cause the inode change time to be set
to the current time. Without a new system call or reading the raw
disk, you can't touch a file without at least one of the timestamps
changing.
}-- End of excerpt from Greg Freemyer
