After a long discussion with a friend I changed some kernel-configs:
* Large Receive Offload (INET_LRO) disabled.
* Changed allocator from SLUB to SLAB
These two made the system much more stable, much less allocation error
messages, but not yet stable enough (still some freezes)
* Increased /proc/sys/vm/min_free_kbytes. was at 8065, changed it to 16000
which made the page allocations nearly disappear at all, with 20000 I
didn't find any message after having copied more than 500GB. But still one
freeze :-(
* Tried kernel boot parameter "noapic". Copied 500GB without any problem. No
freeze, no page alloc error, no transmit timeout in rtl8169 driver.
With this configuration I consider the problem as solved.
Greetings and thanks to all who answered me
Alex
