Hello,
in between I was able to narrow the error down to a quite simple testcase.
1) create a NFS mount inside a VM that uses the IPOIB network interface of the ESX host.
2) copy data via scp from somwhere into this machine onto the NFS mount
When the error occurs for the first time, one can read from the vmkernel.log:
WARNING: LinDMA: Linux_DMACheckContraints:149:Cannot
map machine address = 0x15ffff37b0, length = 65160
for device 0000:02:00.0; reason = buffer straddles
device dma boundary (0xffffffff)
<3>vmnic_ib1:ipoib_send:504: found skb where it does not belong
tx_head = 323830, tx_tail =323830
<3>vmnic_ib1:ipoib_send:505: netif_queue_stopped = 0
Backtrace for current CPU #20, worldID=8212, ebp=0x41220051b028
ipoib_send@<None>#<None>+0x5d4 stack: 0x41800c4524aa, 0x4f0f5000000d
ipoib_send@<None>#<None>+0x5d4 stack: 0x41800c44bca8, 0x41000fe5d6c0
ipoib_start_xmit@<None>#<None>+0x53 stack: 0x41220051b238, 0x41800c4
...
Best regards.
Markus