SMB drops for long open files, Windows 10 and server 2019

[Eds89]

Hi,

I used to have this issue before in FreeNAS 11.x, but an update seemed to fix it and I never truly identified the cause from logs.
I've recently updated to TrueNAS core 12.0-U1, and started having the same kinds of problems again and after some pointers on how to diagnose:

From a Windows server 2019 machine, that has long open files/sessions, my application frequently reports read from disk errors for files being access over SMB on my TrueNAS box.
If I have the app restart or reinitiate connections to those files, all is well for a while longer, and then some seemingly random amount of time later the same error ocurrs.
I have also found on a few occasions, copying files from my Windows 10 machine will start writing, but then I get a general write error and have to cancel and reattempt the copy (I'll get the exact error text on next occurence).

Where should I be looking log wise for these SMB issues, and what should I be looking for?
Is it a possible regression of a previously fixed issue?

Many thanks
Eds

 

[Eds89]

Anyone able to point me in the right direction please?

 

[Samuel Tai]

A little bit more information please:

1. Specs for your TrueNAS build
2. Are both devices in the same Active Directory domain, or are you using local accounts on the TrueNAS box?
3. If both are in the same Active Directory domain, is the time the same on both, and from where are they getting time sync?
4. Output of testparm -s on your TrueNAS box
5. Is anything logged in /var/log/samba4/log.smbd?

 

[anodos]

Possibly an SMB regression that's present in U1.1 related to timers. It's fixed for U2 (which should be released this upcoming week). If you want to test a dev snapshot prior to release, send me a PM and I'll give testing instructions.

 

[Eds89]

Thanks Anodos. It felt like a regression of some kind to me, as it only kicked in after the update.
If the release is likely to be that soon, I'm happy to hang fire until an official release to see if it corrects the behaviour.

Cheers!