With Windows 7, Only Half of Samba Stops Working

It Half Works

Windows 7 is out, and everyone says they are going to upgrade, finally. What does this mean for your Samba servers? In this article we will talk about our experience using Windows 7 with Samba, both as a domain controller and as a basic file server.

Samba is not important just for those rogue sysadmins who try to avoid buying Windows Server products. Samba is used by storage appliance manufacturers and within a wide variety of other embedded devices. Samba interoperability is therefore important for both IT shops that run Linux servers, and businesses that sell Linux-based devices. Microsoft may not, contrary to popular belief, intentionally break Samba, but updates to the protocol and client default settings (due to complaints about security in the Windows world) often leave Samba unable to operate, which brings us to some good news:

This time, with Windows 7, only half of Samba stops working.

Accessing Samba Shares

Accessing Samba shares from Windows 7 "just works." That is, assuming you're running a relatively recent version of Samba. Samba 3.3.2, which ships with Ubuntu Jaunty, works perfectly with Windows Vista and therefore Windows 7 (they are the same, really). In testing, we had no problem connecting to various different Samba servers and Windows XP-based shares.

If you are stuck with an older version of Samba and cannot upgrade, workarounds do exist. Many NAS devices still run Samba 2.x, and do not have an upgrade mechanism. Before modifying all your Windows 7 machines' registries, it is worth checking with the manufacturer of your storage device to inquire about an upgrade. Failing that, you must "degrade" Windows 7.

Go to: Control Panel -> Administrative Tools -> Local Security Policy
Select: Local Policies -> Security Options

As shown in Figure 1, there are two settings to change.
"Network security: LAN Manager authentication level" -> Send LM & NTLM responses
"Minimum session security for NTLM SSP" -> uncheck: Require 128-bit encryption

Figure 1. Click for a larger image.

After these two settings have been changed, you will be able to connect to older Samba-based file shares.

If problems still exist, one final thing to try is removing the stored credentials for the Samba share. During testing, it's possible that something strange got "stuck" in there. In the Control Panel -> Credential Manager, find and remove the stored credentials for the Samba server.

The "just works" comment should be true for people with an already-working Samba setup, who need to allow access from new Windows 7 clients. If you are trying this for the first time, we have left out a lot of details. Start the Samba project's own documentation.