76 Posts

June 14th, 2014 12:00

Solution appears to be cifs signing. 

Disabling signing on 2008 R2 does NOT work.  I disabled this rebooted and it still randomly tried to use a signed SMB connection.  Yes, randomly I have SQL agent logs that show hit or miss success with no changes until I set smb signing to auto on the data domain.

#> cifs option set "server signing"  auto

Restart cifs.

8 Posts

June 14th, 2014 08:00

Hi Scot, have u checked your file server on data domain. The problem is with file server on DD . I'll illustrate u better give me a day. Mean while you check your file server on dd. Is it enabled or not

8 Posts

June 14th, 2014 08:00

Check for

cifs option set "server signing"

This option needs to be enabled on the DD side for SMB1 servers

8 Posts

June 14th, 2014 09:00

So its working earlier and now it stopped in mid night.

And is it working on new share?

76 Posts

June 14th, 2014 09:00

I went the other way and disabled signing on the client side. That did not work but I will try dd setting. The thing that I don't understand is how the job could start failing in the middle of the night and never work again.

If I setup a new share with the se perms it works. So what is changing that makes the job fail on multiple windows servers ? My instinct is telling me it would be related to a move in as domain controllers to 2008 a few weeks ago and is just now present a problem some how.

76 Posts

June 14th, 2014 10:00

Yep, strangest thing.

Same host acls, * for user acl new one works old doesn't.

AND if I delete the old share and create a new one with the same name it still doesn't work.

It's like windows 2008 has remembered something about the share and is using that property incorrectly but I can't see what in tcpdump or in messages with smb logging at 9.

8 Posts

June 14th, 2014 12:00

Good to know that finally it worker its the cifs server signing problem..

8 Posts

June 14th, 2014 12:00

Mark my comments as helpful. If I had helped u some way

76 Posts

June 26th, 2014 07:00

This problem is 2 fold. Enabling signed SMB requires fwd and reverse DNS to resolve to a single interface.

So users who have multiple aliases and possible server issues where a deployment system only updates fwd records signed SMB will stop working.  I also had a case where someone re-provisioned a server and it had 2 reverse names so SMB would intermittently fail.

Issue is still ongoing with Signed SMB performance. Looking at disabling it all together.

76 Posts

July 7th, 2014 12:00

After weeks of troubleshooting CIFS performance issues I have completely disabled signed cifs support on the data domain and performance has returned to normal. Change was made based on documented performance issues comparing signed SMB1 vs SMB2. 

Performance symptoms were evident from SQL backup jobs, and standard UNC copies via the guest OS.

https://www.google.com/#q=signed+smb+performance

Support tested iperf and lmdd tools which proved there were no network or SMB1 limitations but neither tool benchmarked signed SMB.

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