Comment 2 for bug 981636

StacktraceTop:
 ped_assert () from /tmp/tmpVcGWq2/lib/x86_64-linux-gnu/libparted.so.0
 ped_device_write () from /tmp/tmpVcGWq2/lib/x86_64-linux-gnu/libparted.so.0
 GParted::GParted_Core::copy_block (this=0x7fff87aba020, lp_device_src=<optimized out>, lp_device_dst=0x7f3cc0012d90, offset_src=427387340, offset_dst=593195008, block_length=<optimized out>, error_message=..., readonly=false) at GParted_Core.cc:2800
 GParted::GParted_Core::copy_blocks (this=0x7fff87aba020, src_device=..., dst_device=..., src_start=545104331, dst_start=710911999, length=193188593664, blocksize=-8388608, operationdetail=..., readonly=false, total_done=@0x7f3cc98e7518) at GParted_Core.cc:2708
 GParted::GParted_Core::copy_filesystem (this=0x7fff87aba020, src_device=..., dst_device=..., src_start=167782860, dst_start=333590528, src_sector_size=512, dst_sector_size=512, src_length=193272479744, operationdetail=..., readonly=false, total_done=@0x7f3cc98e7518) at GParted_Core.cc:2471