HP CIFS Server Administrator's Guide (5900-1282, April 2011)

idmap rid Backend Support
The idmap rid facility with winbind provides a unique mapping of Windows SIDs to local UNIX
UIDs and GIDs. The idmap rid facility uses the RID of the user SID to generate the UID and GID
by adding the RID number to a configurable base value. Since the RIDs are allocated by the
centrally managed Windows Domain Controller, this tool permits the CIFS winbind daemons to
generate unique HP-UX UIDs and GIDs across the domain. It can be used for synchronization of
mappings across multiple CIFS servers without an LDAP directory. You can use the idmap rid
facility in a Windows NT domain or a Windows 2000/2003 ADS domain, but it can not be used
in Windows trusted domains.
In HP CIFS Server A.02.03 or later, the idmap rid shared library, idmap_rid.sl(so), is
changed to rid.sl(so).
Limitations Using idmap rid
• The idmap rid facility is only used in a single Windows domain. It doesn't work with
Windows trusted domains. Using the idmap rid method requires that you set the allow
trusted domains parameter to No.
• You must set the idmap_rid range to be equal to both idmap uid and idmap gid ranges
in the smb.conf file.
• When you set the idmap backend parameter to rid, UIDs and GIDs mapping data is only
stored locally.
Configuring and Using idmap rid
To use the idmap rid method, you must configure the following parameters in the smb.conf
file:
• Set idmap backend to rid:<domain name>=<idmap_rid range>.
• Set allow trusted domains to No.
An example of smb.conf using rid is shown below:
[global]
workgroup = DomainA # Doamin name
security = domain or ADS
# idmap section
idmap uid = 50000-60000
idmap gid = 50000-60000
idmap backend = rid:DomainA=50000-60000
allow trusted domains = no
Check the log file to see if the rid shared library is loaded after you configure and setup rid.
LDAP Backend Support
When multiple CIFS Servers participate in a Windows NT or Windows ADS domain and make
use of winbind, you can configure multiple CIFS Servers to store ID maps in an LDAP directory.
Making use of an LDAP server and configuring CIFS servers with the idmap backend parameter
in smb.conf will ensure that all UIDs and GIDs are unique across the domain. This is important
in order to support Windows access to NFS shares.
106 Winbind Support