I traced down the information and indeed I have had this problem as well when copying more then 50 thousand files
So your problem is confirmed.
The problem is caused by this, when copying files samba writes data in the files
connections.tdb
locking.tdb
which are present in /rw_fs/tmp/usr/var/locks
Especially the locking.tdb file grows, with each file copied since last boot it becomes 100 byte bigger so after about 50 thousand files it reaches a size of 5MB and then the problem occurs and you get the error no space left on device.
This because we have mounted a ramdisk with name tmpfs on /rw_fs/tmp/usr/var with size of 5MB. This is done to prevent unnecessary disk spin ups as samba seem to write to some files in there even when no files are being transferred.
So all files in /rw_fs/tmp/usr/var/ (incl sub folders) cannot become larger the 5 MB.
When the locking and connection.tdb have grown to occupy all the free space of the ramdisk samba will abort. Only after reboot it will work again because then these files are deleted and reset.
I made a new rcS file that will move these two file from the ramdisk to the normal disk, probably it will not affect the disk standby performance as I think that these files are only written to in case there are file transfer made by the samba server (
Attached an adapted rcS file
Replace the one in /etc/init.d by this one (be sure that after replacing it tit still has executable rights)
After installing it reboot your nwsp2 and try again to copy the files...should work now
---edit 25 march 16
file removed, use the patch file to repair this bug
viewtopic.php?f=7&t=2326#p22293