Large file read errors with cifs

[Peter Jones]

This relates to reading files from a Netgear NAS server on a local network. I am running on a desktop PC, originally with ubuntu 12.x subsequently updated to 13.10.

Under 12.x I mounted sections of the NAS server as Windows shares using samba and everything worked fine.

When I upgraded to 13.10 (via 13.04?) I found that the NAS was not mounting. On investigation I found that samba was no longer supported and that I should use cifs. The was no warning that this was going to happen before or during the upgrade.

The shares mounted OK and things were fine with normal docs. However with photos and large files reading failed with errors like 'Input/output error". Transfers were fine on other pcs connected to the NAS server. The error occurs both with nautilus and cp in a bash shell. Sometime it is OK on a reboot but soon becomes corrupt.

On searching for possible solutions there seemed to be one possibility related to 'optimistic locking' but I could not make it work.

The mount instructions in /etc/fstab are of the form:

//nas1/photos /media/photos_nas1 cifs sec=ntlm,credentials=/home/peter/.nas1cred
entials,uid=1000,gid=1000,cache=none