SMB Share freeze

Hi everyone,

We encountered some difficulties with SMB Shares on El Capitan server with few customers.

Context :

Server : OS X El Capitan with server.app, both up-to-date.

Services enable :

- Open Directory

- DHCP

- DNS

- FileSharing (SMB)

- Caching

Client : OS X El Capitan up-to-date.

SMB Share are well mounted using SMBv3 (check using "smbutil statshares -m /Volumes/SMBShare")

After about 4 days uptime on the server, clients that access to SMB Share have some freeze (from 30 secondes, to 5 minutes) both in Finder and Terminal without understanding why.

Activity monitor and Stats view in server.app show nothing particular (CPU, Network bandwith, RAM - all OK).

If the volume is unmounted/mounted again on the client, things going better for about half day, and if we restart the server, things are going better for few days (about 4).

Does someone experience this issue and how to fix it ?