[gentoo-user] Re: CIFS mounts started misbehaving

[Grant Edwards]

On 2017-03-04, Kai Krakow <hurikhan77@×××××.com> wrote:
> Am Sat, 04 Mar 2017 08:02:11 +0000 schrieb "J. Roeleveld" <joost@××××××××.org>:
>
>>
>> >Normally, when things are working but idle, the TCP connection to 445
>> >shows an SMB echo request/rseponse transaction once per minute.  When
>> >it fails, the TCP connection evidently got dropped, and the Windows
>> >machine repeatedly shuts down new ones:
>> >
>> >The failure mode looks like this in wireshark:
>> >
>> >  Gentoo                            Windows
>> >
>> >          ->         SYN          ->  445
>> >         <-        SYN/ACK       <-   445
>> >          ->         ACK          ->  445
>> >          ->     SMB[echo req]    ->  445
>> >         <-          RST         <-   445
>> >
>> >[that repeats 800 times per second for long periods of time]
>> >
>> >Then at some point, it starts to work:
>> >
>> >          ->        SYN          ->  445
>> >         <-       SYN/ACK       <-   445
>> >          ->        ACK          ->  445
>> >          -> SMB[proto neg req]  ->  445
>> >         <-  SMB[proto neg rsp] <-   445
>> >          -> SMB[ses setup req]  ->  445
>> >         <-  SMB[ses setup rsp] <-   445
>> >                     ...
>>
>> >Sometimes the umount times out and "fails" because the "host is
>> >down", and when that happens, it seems like it immediately starts to
>> >work again. :/
>>
>> Are other hosts linux or windows?

Other Linux and Windows clients don't seem to be having this problem.

>> Maybe a dodgy switch forgetting the correct path?

I don't think so.  I can ping the host while the CIFS subsystem says
"host is down".  If the switch is forgetting the path, who's sending
back the SYN/ACK and the RST

> Or an MTU problem... Is there a router in the path?

Nope.

I'm going to try to set up a Wireshark capture in ring-buffer mode and
somehow detect the failure and stop the capture...

-- 
Grant