Re: unexpected behavior of cp and mv
On Wed 29 Apr 2020 at 15:07:52 (-0400), Alberto Sentieri wrote:
> When I tried strace with /bin/cp -pi I can see on both commands
> something like this:
>
> utimensat(4, NULL, [{tv_sec=1588174263, tv_nsec=908624390} /*
> 2020-04-29T11:31:03.908624390-0400 */, {tv_sec=1486350336,
> tv_nsec=481422339} /* 2017-02-05T22:05:36.481422339-0500 */], 0) = 0
>
> The utimensat is exactly the same for both cp -pi to a ext4 file
> system or to a smb filesystem. So, cp seems to be working as expected.
> Probably the same is true to /bin/mv.
There's no possibility, is there, that you're reading the file status
time rather than the file modification time? cp -ip/mv will update the
former though not the latter. All three times will be set by touch in
the absence of any options (c and m).
I'm not familiar with cifs/smb protocols and filesystems.
> -----------------------------------------------------------------
>
> Exactly the same behavior for /bin/cp and /bin/mv. I do not have any other cp or mv in my path.
>
> $ sha1sum /bin/cp /bin/mv
> 220687a082fb9d0dbb48e9a2b1093cbb4e9de55a /bin/cp
> 46e71d67df7eb1c41f8f8c9039f401e242cce94a /bin/mv
>
>
> On Wed, Apr 29, 2020 at 12:22:41PM -0400, Alberto Sentieri wrote:
> > cp and mv are not preserving the file timestamps when copying from a ext4
> > file system to a smb file system.
> >
> > I am running cp and mv on:
> > $ lsb_release -a
> > No LSB modules are available.
> > Distributor ID: Debian
> > Description: Debian GNU/Linux 10 (buster)
> > Release: 10
> > Codename: buster
> >
> > SMB is running on:
> > $ lsb_release -a
> > No LSB modules are available.
> > Distributor ID: Debian
> > Description: Debian GNU/Linux 9.12 (stretch)
> > Release: 9.12
> > Codename: stretch
> >
> > I am using "cp -pi" to copy the files and "mv -i" to move them.
> >
> > If I run cp or mv on a Debian stretch, time stamps will be correct on the
> > SMB file system.
> >
> > Buster gnome3 file manager will copy or move the files without problems, I
> > mean, they will preserve time stamps.
> >
> > This started happening since I upgraded my workstation to buster, so the
> > problem seems to be in buster. I am mounting the file system on buster with
> > the following line added to fstab, which, by the way, is the same I was
> > using when my workstation was running stretch:
> >
> > //192.168.1.2/alberto /mnt/u1/rw cifs
> > credentials=/root/pass/alberto.pass,uid=alberto,gid=alberto,rw 0 0
> >
> > Does anyone knows which package is causing this behavior?
> >
> First, do you see the same behavior if you use /bin/cp and /bin/mv
> instead of simply cp and mv?
Cheers,
David.
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