We have multiple Mac OS/OSX servers (A mix of El Cap and High Sierra) that have SMB shares mounted for backing /archiving jobs (chronosync and P5)

The SMB shares are connected via "connect to server" and generally remain stable, but become unmounted randomly at least once every 1-2 days.

My question: Is there any way analyse the logs (We've looked in system.log) and find the reason for the unmount?

The goal here is to keep the SMB shares mounted at all cost.

I've read around on StackExchange and tried analysing the network connections using the command from this post:

SMB: auto-unmount then unable to re-mount without restart

netstat -I
ping -c 90 -i 10 your_SMB_server
tail -f /var/log/system.log

No errors or issues with the packets found.

I'm sure there's a sys admin expert out that must have solved this already ;)

Appreciate any suggestions or ideas, however rudimentary


  • What's the server? Are you sure the server isn't kicking them off, perhaps if inactive?
    – benwiggy
    Mar 8, 2019 at 14:40
  • +1 for more info in the sever. For instance, there is a config option in Samba which disconnects inactive connections after a certain period of time. Also, it would probably make more sense to look at the sever logs.
    – Gummibando
    Mar 8, 2019 at 18:46
  • Thanks for the response guys, super helpful. Seems logical to reason that the disconnects would be logged with the server rather than the client. These are ReadyNAS, Synology and TigerBox storage, all using SMB shares. I'll look into the SMB settings and logs of the servers and report back here
    – beano
    Mar 11, 2019 at 10:22

1 Answer 1


Not certain I understand the context of your question, so let's try this first:

This has worked for me:

  1. Mount the SMB/CIFS share using Finder's Go, Connect to Server....
  2. If prompted for credentials, and given the option, store those credentials in the Keychain
  3. Open System Preferences, Users and Groups; select the Login Items tab near the top
  4. Click the + button at the bottom of the list of login items to "add" an item.
  5. This will produce a new Finder window that allows you to select an item. Simply navigate to the mounted SMB/CIFS share from the Sidebar, select/highlight the SMB/CIFS share of interest, then click the Add button in the bottom right of the Finder window.

This should dismiss the Finder window, and now the share should be mounted at each login. Let us know if this doesn't work/isn't what you needed.

  • Thanks for the response, this is exactly how these shares are connected, using these exact steps. Under these connections, we find the shares are unmounted, sometimes overnight. We're seeing this with Netgear ReadyNAS, Synology and TigerBox storage, all using SMB shares. Across a mix of El Cap, Yosemite and High Sierra OS's, the OS appears to make no difference. The main question here, is how to investigate the problem and find the status message at the point of the disconnect.
    – beano
    Mar 11, 2019 at 10:17
  • @beano: Sorry that didn't work... I didn't know what you'd tried, so I thought it best to start simple. FWIW, this has bugged me in the past, but seems less a problem (for me anyway) since High Sierra. Still an interesting problem though... IMHO, looking for revealing log entries may yield nothing, so I'd tend to stick with attacking the problem directly. To that end, here's a link that might help..
    – Seamus
    Mar 12, 2019 at 18:00
  • @beano: Here's another potential approach that might help. From reading the comments, it seemed to help some people. Check out man auto_master to get started, and read Apple's white paper on AutoFS
    – Seamus
    Mar 12, 2019 at 19:10
  • Thanks for the incredibly useful post, I'd discovered auto_master but these posts provide a really detailed guide @Seamus I'm avidly reading through these now and will look to implement this week :D
    – beano
    Mar 18, 2019 at 12:05
  • @beano: Cool! This problem has been lying around for years. So many questions have been posted, and so few (virtually none ACAICT) effective answers. I'll look forward to hearing your results.
    – Seamus
    Mar 18, 2019 at 12:30

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