[linux-cifs-client] Errors popping up under heavy load

[Sam Liddicott]

I know that the windows server may drop the connection if there is more 
than around 150 outstanding requests from the same IP - it assumes the 
client is abusive, I think. (I don't know if this is just per ip or per 
ip/mid combination).

Before it drops the connection it may throttle responses.

The client may need to do some resource management.

Sam

* Michael Muratet wrote, On 03/03/09 12:32:
>
> On Mar 3, 2009, at 6:06 AM, Jeff Layton wrote:
>
>> On Tue, 24 Feb 2009 06:17:48 -0600
>> Michael Muratet <mmuratet at hudsonalpha.org> wrote:
>>
>>> Greetings
>>>
>>> I have Promise 48TB RAID system connected to MacPro and CIFS mounted
>>> to a Dell 1950 8-core running RedHat Enterprise 3. I was not so much
>>> worried about security, but it did seem to perform better than NFS,
>>> for instance. It has worked well up until now. We recently had to
>>> migrate some large apps from the Mac to the linux box because a vendor
>>> no longer supports the Mac which puts a lot of traffic through the
>>> mount. Yesterday we starting seeing errors:
>>>
>>
>> Sorry for the late response...
>
> Jeff
>
> No worries, thanks for the response
>>
>>
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: No response to cmd 46 mid
>>> 62979
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: No response to cmd 46 mid
>>> 62980
>>
>> Client sent an error and timed out before the server responded...
>
> Could this be a latency issue?
>>
>>
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: Send error in read = -11
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: Send error in read = -11
>>
>> We tried to send on the socket, but couldn't. -EAGAIN == -11, which
>> means "try again later".
>>
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: No response to cmd 47 mid
>>> 62978
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: No response to cmd 47 mid
>>> 62977
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: No response to cmd 47 mid
>>> 62976
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: No response to cmd 47 mid
>>> 62975
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: No response to cmd 47 mid
>>> 62974
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: No response to cmd 47 mid
>>> 62973
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: No response to cmd 46 mid
>>> 62972
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: Send error in read = -11
>>> Feb 23 09:25:59 srv-cf1 kernel:  CIFS VFS: Send error in read = -9
>>>
>> -9 == -EBADF, bad filehandle. Client tried to reissue the read but the
>> filehandle is now bogus? Maybe the socket got reconnected and we haven't
>> reclaimed the file yet?
>>
>>> Have I reached the limits of CIFS capability? I've been poking around
>>> the web trying to find a manual that describes these errors. Can
>>> someone point me to a manual or tell me what the errors mean?
>>>
>>
>> Basically it looks like the server is going unresponsive, and/or is
>> closing its TCP receive window so that we can't send requests to it.
>> That said there were some bugs in earlier kernels that could cause
>> messages like this to pop due to alignment issues.
>>
>
>
>> What kernel is the client running here?
>
> Linux srv-cf1.haib.org 2.6.9-55.ELsmp #1 SMP Fri Apr 20 16:36:54 EDT 
> 2007 x86_64 x86_64 x86_64 GNU/Linux
>
> Thanks
>
> Mike
>
>>
>>
>> -- 
>> Jeff Layton <jlayton at redhat.com>
>
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