[Samba] Files larger than 1GB fail to copy

[Jeremy Allison]

On Wed, Jun 24, 2015 at 06:33:06PM +1000, Phill Edwards wrote:
> I have a QNAP TS-410 NAS on which I have some CIFS shares. I'm trying to
> copy some biggish files from a Lunix machine to the CIFS share on the NAS
> but have runs into problems. I've created files of various sizes and I've
> found that I can copy files up to size 1024MB to the CIFS share on the NAS,
> but when I try to copy anything larger than that the copy command hangs
> forever and nothing happens. This is reproducible in my setup and happens
> consistently.
> 
> I've also found an error message on the NAS in /var/log/log.smbd which
> might shed some light, but it doesn't mean anything to me and Googling
> hasn't helped me solve it:
> 
> [2015/06/24 18:12:00.048030,  0] smbd/process.c:245(read_packet_remainder)
>   read_fd_with_timeout failed for client 192.168.0.103 read error =
> NT_STATUS_END_OF_FILE

That just means the client didn't send data when the server expected it
to, so we timed out the read.

> I've also tried setting up an NFS share on the NAS and copying large files
> to that - this works fine, so it seems to be something to do with Samba.
> Can anyone advise what might be wrong here?

Smells like a Linux kernel cifsfs client bug to me. I hate to
suggest it but could you try copying the same files from
Windows (transfer them to the windows client on a memory
stick). I'm guessing that will work well to the QNAP, which
would confirm it's a cifsfs bug. At that point you need
to bug your distro vendor :-).