I have an OS X client that is able to mount to SMB shares, but then arbitrarily disconnects. Sometimes the shares can stay mounted for hours, sometimes only 15 seconds. There doesn't seem to be any particular process that's causing the disconnections.
- Client is Mac OS X 10.11.6 (15G1004) client on a MacPro5,1.
- Client's NIC is an ATTO FastFrame NT12, with driver ATTOFastFrame.kext installed [v. 3.0.7]
- Client signing is disabled on the client as per Apple's slow SMB signing: https://discussions.apple.com/message/30287193#message30287193
- Server is a downstream derivative of FreeNAS 9.3 running Samba 4.3.6-GIT-UNKNOWN
- Shares are mounted as SMB3_02
- 10 GbE switch is NETGEAR ProSafe M7100-24x
Other OS X clients have no such issues on the same network and the same server with a Sonnet Twin 10G.
Other possibly relevant details:
- Boot drive is an OWC Mercury Accelsior with the driver properly installed, so there should be no power issues: https://eshop.macsales.com/tech_center/index.cfm?page=/manuals/item/owcaccelsior.html
- GPU is a 2014 NVIDIA GeForce GTX TITAN X with the MacVidCards firmware
- The disconnects are noticed while using Adobe Premiere Pro and Blackmagic DaVinci Resolve
Why might these disconnects be occurring in this way?
Turns out the fan inside the MacPro5,1 for the expansion slots had died and the NVIDIA GeForce GTX TITAN X was likely bringing the other PCIe components to temperatures above their operating temperatures. Replacing the OEM fan for the expansion slots seems to have fixed the problem entirely, but just for good measure, I've decided to leave the side panel off and add two extra fans for exhaust, since the MacPro5,1 was not designed for hotter, powerful video cards like the TITAN X.