Fwd: backing up to a Drobo CIFS VFS: Error -11 sending data on socket to server, Bufferbloat?

[Robert Kudyba]

>> You will likely see it better in wireshark by using Statistics->I/O
>> Graph as it will show you where the throughput rate drops to zero.
>>
>> Then you can click on the graph at the point where it drops to zero to
>> get the main window to go to that packet and then you can relate it to
>> the tshark output.

I posted the graph at storm.cis.fordham.edu/~rkudyba/wireshark.pdf

>> The earliest message you posted suggests that the client (Linux) was
>> complaining of no activity for 120 seconds, which suggests that the
>> Drobo stopped responding at some point. Thus I would expect to see one
>> or more writes that did not get responses, followed by a connection
>> drop and reconnect.

Some random messages from tshark not exactly sure what I'm looking for
as the time stamps aren't easy to interpret:
41674 217.172644 drobo → localserver SMB 117 [TCP ACKed unseen
segment] Write AndX Response, FID: 0x4ca4, 65536 bytes
41702 217.177652 localserver → drobo SMB 14546 Write AndX Request,
FID: 0x4ca4, 65536 bytes at offset 54329344[TCP segment of a
reassembled PDU]
41726 217.183095 drobo → localserver SMB 117 Write AndX Response, FID:
0x4ca4, 65536 bytes
 4156 136.143502 drobo → localserver SMB 252 Trans2 Response<unknown>
 4254 161.145741 drobo → localserver SMB 117 [TCP ZeroWindow] Write
AndX Response, 65536 bytes
 4260 161.147530 drobo → localserver SMB 117 Write AndX Response, 65536 bytes
 4566 161.219832 drobo → localserver SMB 117 [TCP ACKed unseen
segment] Write AndX Response, 65536 bytes
 4594 161.225586 drobo → localserver SMB 117 Write AndX Response, 65536 bytes
 4690 162.010514 drobo → localserver SMB 117 [TCP ZeroWindow] Write
AndX Response, 65536 bytes
 4696 162.011564 drobo → localserver SMB 117 Write AndX Response, 65536 bytes
 4697 162.011830 drobo → localserver SMB 204 Trans2 Response<unknown>
 1056   4.654442 drobo → localserver SMB 117 [TCP ACKed unseen
segment] [TCP Previous segment not captured] Write AndX Response,
65536 bytes
 1057   4.660219 drobo → localserver SMB 117 [TCP ACKed unseen
segment] Write AndX Response, 65536 bytes
 1082   4.808276 drobo → localserver SMB 117 [TCP ACKed unseen
segment] [TCP Previous segment not captured] Write AndX Response,
65536 bytes
  2718  33.792075 localserver → drobo SMB 14546 Write AndX Request,
FID: 0x38ff, 65536 bytes at offset 167563264[TCP segment of a
reassembled PDU]
 2723  33.795265 localserver → drobo SMB 20338 Write AndX Request,
FID: 0x38ff, 65536 bytes at offset 167628800[TCP segment of a
reassembled PDU]
 2726  33.806707 drobo → localserver SMB 117 [TCP ACKed unseen
segment] Write AndX Response, 65536 bytes
 2727  33.806736 drobo → localserver SMB 117 Write AndX Response, 65536 bytes
 2730  33.807123 localserver → drobo SMB 17442 Write AndX Request,
FID: 0x38ff, 65536 bytes at offset 167694336[TCP segment of a
reassembled PDU]
 2736  33.811345 localserver → drobo SMB 8754 Write AndX Request, FID:
0x38ff, 65536 bytes at offset 167759872[TCP segment of a reassembled
PDU]
 2739  33.814173 drobo → localserver SMB 117 Write AndX Response, 65536 bytes
 2744  33.818007 localserver → drobo SMB 13098 Write AndX Request,
FID: 0x38ff, 65536 bytes at offset 167825408[TCP segment of a
reassembled PDU]
 41544 300.578408 localserver → drobo SMB 5858 Write AndX Request,
FID: 0x38ff, 65536 bytes at offset 2089480192[TCP segment of a
reassembled PDU]
41548 300.582822 drobo → localserver SMB 117 Write AndX Response, 65536 bytes
41551 300.584432 localserver → drobo SMB 13098 Write AndX Request,
FID: 0x38ff, 65536 bytes at offset 2089545728Write AndX Request, FID:
0x38ff, 4096 bytes at offset 2089828352
41555 300.589855 drobo → localserver SMB 117 Write AndX Response, 65536 bytes
41558 300.590108 localserver → drobo SMB 13098 Write AndX Request,
FID: 0x38ff, 65536 bytes at offset 2089611264[TCP segment of a
reassembled PDU]
41559 300.594149 drobo → localserver SMB 117 Write AndX Response, 65536 bytes
41560 300.594438 drobo → localserver SMB 129 Write AndX Response, 4096 bytes
41584 300.602694 drobo → localserver SMB 129 [TCP ACKed unseen
segment] Write AndX Response, 65536 bytes