Windows Server 2019 SMB client loses access to Hitachi HNAS share (BizTalk workload)

Question

Hello,

I have Windows Server 2019 with biztalk for client side that write and read files on a nas folder from Hitachi version 14.9.

The server biztalk wrote on example a folder shared name mapped on \domain.int.local.xxx\sharefolder\test\test2

My problem is that after each day(less than 16 hours) , my shared folder become not available. I have to restart the service workstation to release the smb session/connections.

I am troubleshooting an SMB stability issue between Windows Server 2019 (BizTalk) and a Hitachi HNAS 14.x.

Details :

Environment

• Windows Server 2019 (SMB client)
• BizTalk Server (high file read/write workload)
• Hitachi NAS (HNAS) 14.x
• SMB protocol: mostly SMB 3.1.1, some 3.0.2
• Authentication: Kerberos
• NIC: VM (vmxnet3)
• NAS accessed via a single SMB alias/share

Problem

Under load, the SMB share hosted on the Hitachi NAS becomes unavailable from the Windows Server 2019 client.

Symptoms:

• BizTalk file operations stall
• Access to the NAS share fails
• Restarting the Workstation (LanmanWorkstation) service restores access
• Other NAS shares (less loaded) continue to work normally