A fix for slow connections to SMB file shares on Mac OS X Snow Leopard
In Mac OS X 10.6 Snow Leopard, I found it takes a long time (30 seconds or more) to connect to a shared folder on my Windows server.
Once connected, everything works fine, but the initial delay is a big hassle.
Please note: There is a different problem where the actual file sharing is slow (or browsing between folders is slow). I have not had that problem so I don’t know the solution. The problem I am fixing is that the initial connection to the SMB share takes a long time.
The Solution
Ignore what I wrote before. I have found the definitive solution (for my network, at least).
The solution is: don’t use a .local name for your Windows domain. .local for your Windows domain is evil. Use a real domain name that you control.
Yes, I know that the example documentation shows domains named company.local. I know it can be a major pain-in-the-tuchus to change the Active Directory domain name (and may not even be possible if you’re using Exchange Server).
But after changing our AD domain name from company.local to hq.company.com, our Macs were miraculously faster at mounting network shares, browsing the network, and joining the domain.
Note that hq.company.com is a DNS subdomain of our real DNS domain name (obviously replace company.com with the company name that I work for). It is only resolvable by our internal AD DNS servers, so there’s no chance of exposing internal hostnames to the world.
The solution (for me) was to create a file called /Library/Preferences/edu.mit.Kerberos with the following contents:
[libdefaults] default_realm = your-domain.local dns_fallback = no
Replace your-domain.local with your Windows/Active Directory domain name.
After saving the file, the fix takes effect immediately. Connecting to the share dropped from about 30 seconds to about 5 seconds.
Some notes:
* The server is Windows Server 2008 R2.
* The Mac is not joined to the domain. (I am authenticating as a domain user, of course.)
I originally found this information on MacWindows. There is an extremely long thread there and this was one of the solutions that came up.
## Update ##
At some point under 10.6 this stopped working. I am now running 10.7 Lion and this solution no longer works. I am back to slow connections.
