CIFS

The Common Internet File System (CIFS) is a network protocol that offers file services for (typically) Windows computers. Unix-like systems that provide a CIFS client can also connect to CIFS shares. Before configuring this service, you should first create your CIFS shares in Sharing → Windows (CIFS) Shares → Add Windows (CIFS) Share. After configuring this service, go to Services → Control Services to start the service. The CIFS shares will not be available on the network if this service is not running.

NOTE: after starting the CIFS service, it may take several minutes for the master browser election to occur and for the FreeNAS® system to become available in Windows Explorer.

Starting this service will open the following ports on the FreeNAS® system:

• TCP 139 (smbd)

• TCP 445 (smbd)

• UDP 137 (nmbd)

• UDP 138 (nmbd)

Figure 8.4a shows the configuration options which are described in Table 8.4a. This configuration screen is really a front-end to smb.conf(5).

Figure 8.4a: Configuring CIFS

Table 8.4a: CIFS Configuration Options

Setting	Value	Description
Authentication Model	drop-down menu	choices are Anonymous or Local User; this setting is ignored if the Active Directory or LDAP service is running
NetBIOS Name	string	must be lowercase and should be same as the hostname on the FreeNAS® system; it must be different from the Workgroup name
Workgroup	string	must match Windows workgroup name; this setting is ignored if the Active Directory or LDAP service is running
Description	string	optional
DOS Charset	drop-down menu	the character set Samba uses when communicating with DOS and Windows 9x/ME clients; default is CP437
UNIX Charset	drop-down menu	default is UTF-8 which supports all characters in all languages
Log Level	drop-down menu	choices are Minimum, Normal, Full, or Debug
Local Master	checkbox	determines whether or not the FreeNAS® system participates in a browser election; should be disabled when network contains an AD or LDAP server and is not necessary if Vista or Windows 7 machines are present
Time Server for Domain	checkbox	determines whether or not the FreeNAS® system advertises itself as a time server to Windows clients; should be disabled when network contains an AD or LDAP server
Guest Account	drop-down menu	account to be used for guest access; that account must have permission to access the shared volume/dataset
File mask	integer	overrides default file creation mask of 0666 which creates files with read and write access for everybody
Directory mask	integer	overrides default directory creation mask of 0777 which grants directory read, write and execute access for everybody
Send files with sendfile(2)	checkbox	newer Windows versions support the more efficient sendfile system call which makes Samba faster
EA Support	checkbox	enables extended attributes
Support DOS File Attributes	checkbox	allows a user who has write access to a file to modify the permissions, even if not the owner of the file
Allow Empty Password	checkbox	if checked, users can just press enter when prompted for a password; requires that the username/password be the same for the FreeNAS® user account and the Windows user account
Auxiliary parameters	string	smb.conf options not covered elsewhere in this screen; see the Samba Guide for additional settings
Enable home directories	checkbox	if checked, a folder with the same name as the user account will be created for each user
Enable home directories browsing	checkbox	users can browse (but not write to) other users' home directories
Home directories	browse button	select volume/dataset where the home directories will be created
Homes auxiliary parameters	string	options specific to the [homes] section of smb.conf; for example, hide dot files = yes hides files beginning with a dot in home directories
Unix Extensions	checkbox	allows non-Windows CIFS clients to access symbolic links and hard links, has no affect on Windows clients
Enable AIO	checkbox	enables asynchronous I/O in FreeNAS® versions 8.0.3-RELEASE and higher; enabling this reduces CIFS speed in some networks
Minimum AIO read size	integer	default is 4096 bytes; Samba will read asynchronously when size of request is bigger than this value
Minimum AIO write size	integer	default is 4096 bytes; Samba will write asynchronously when size of request is bigger than this value
Zeroconf share discovery	checkbox	enable if Mac clients will be connecting to the CIFS share
Hostnames lookups	checkbox	allows you to specify hostnames rather than IP addresses in the Hosts Allow or Hosts Deny fields of a CIFS share; uncheck if you only use IP addresses as it saves the time of a host lookup

Beginning with FreeNAS® 8.0.3-RELEASE, changes to CIFS settings and CIFS shares take effect immediately. For previous versions, changes will not take effect until you manually stop and start the CIFS service.

NOTE: do not set the directory name cache size as an auxiliary parameter. Due to differences in how Linux and BSD handle file descriptors, directory name caching is disabled on BSD systems in order to improve performance.

Troubleshooting Tips

Compared to other networking protocols, CIFS is not fast. Enabling the following checkboxes may help to increase network throughput: Large RW support, Send files with sendfile(2), and Enable AIO. Adjusting the Minimum AIO read and write size settings to better fit your networking infrastructure may improve or degrade performance.

Samba's "write cache" parameter has been reported to improve write performance in some configurations and can be added to the Auxiliary Parameters field. Use an integer value which is a multiple of _SC_PAGESIZE (typically 4096) to avoid memory fragmentation. This will increase Samba's memory requirements and should not be used on systems with limited RAM.

If you wish to increase network performance, read the Samba section on socket options. It indicates which options are available and recommends that you experiment to see which are supported by your clients and improve your network's performance.

Windows automatically caches file sharing information. If you make changes to a CIFS share or to the permissions of a volume/dataset being shared by CIFS and users are no longer able to access the share, instruct the users to log out and back into their Windows systems.

Where possible, avoid using a mix of case in filenames as this may cause confusion for Windows users. Representing and resolving filenames with Samba explains this in more detail.

The Common Errors section of the Samba documentation contains additional troubleshooting tips.