Difference between revisions of "Setting up Samba as a Domain Member"

m (/* added extra note to 'mapping the domain Administrator')
m (/* typo)
 
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 +
{{Imbox
 +
| type = important
 +
| text = Never use <code>samba-tool domain provision</code> to create a Unix domain member, it will not work, you must follow the procedure laid out on this page.
 +
}}
 +
 +
{{Imbox
 +
| type = important
 +
| text = All AD Domain members must be in the same <code>DNS</code> domain and the Realm must be the <code>DNS</code> domain in uppercase.
 +
}}
  
  
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* If you previously run a Samba installation on this host:
 
* If you previously run a Samba installation on this host:
:* Remove the existing <code>smb.conf</code> file. To list the path to the file, enter:
+
:* Backup the existing <code>smb.conf</code> file. To list the path to the file, enter:
  
 
  # smbd -b | grep "CONFIGFILE"
 
  # smbd -b | grep "CONFIGFILE"
Line 46: Line 55:
 
=== Configuring DNS ===
 
=== Configuring DNS ===
  
For details, see [[Linux_and_Unix_DNS_Configuration|Linux and Unix DNS Configuration]].
+
{{:Linux and Unix DNS Configuration}}
 +
 
 +
 
  
  
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The previous example configures Kerberos for the <code>SAMDOM.EXAMPLE.COM</code> realm.
 
The previous example configures Kerberos for the <code>SAMDOM.EXAMPLE.COM</code> realm.
  
The Samba teams recommends not setting further parameters in the <code>/etc/krb5.conf</code> file.
+
The Samba teams recommends to no set any further parameters in the <code>/etc/krb5.conf</code> file.
 +
 
 +
If your <code>/etc/krb5.conf</code> contains an <code>include</code> line it will not work, you '''Must''' remove this line.
  
  
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Kerberos requires a synchronised time on all domain members. Thus it is recommended to set up an NTP client. For further details, see [[Time_Synchronisation#Configuring_Time_Synchronisation_on_a_Unix_Domain_Member|Configuring Time Synchronisation on a Unix Domain Member]].
 
Kerberos requires a synchronised time on all domain members. Thus it is recommended to set up an NTP client. For further details, see [[Time_Synchronisation#Configuring_Time_Synchronisation_on_a_Unix_Domain_Member|Configuring Time Synchronisation on a Unix Domain Member]].
 +
 +
  
  
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{{Imbox
 
{{Imbox
 
| type = note
 
| type = note
| text = The RFC2307 attributes are not added automatically when users or groups are created.
+
| text = The RFC2307 attributes (<code>uidNumber</code>, <code>gidNumber</code>, etc) are not added automatically when users or groups are created, you must add them manually.
 
}}
 
}}
 +
 +
 +
{{Imbox
 +
| type = important
 +
| text = The ID numbers found on a DC (numbers in the 3000000 range) are NOT rfc2307 attributes They cannot and will not be used on Unix Domain Members, if you want to have the same ID numbers everywhere, you must add uidNumber & gidNumber attributes to AD and use the winbind 'ad' backend on Unix Domain Members. If you do decide to add uidNumber & gidNumber attributes to AD, you do not need to use numbers in the 3000000 range and in fact it would definitely be a good idea to use a different range.
 +
}}
 +
  
  
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   CONFIGFILE: /usr/local/samba/etc/smb.conf
 
   CONFIGFILE: /usr/local/samba/etc/smb.conf
  
* After reading this wikipage, edit the <code>smb.conf</code> file and use this example configuration as a basis to set yours, do not just 'cut & paste' it:
+
To create a basic smb.conf, you need something like this (note, this does not include any 'idmap config' auth lines, they will be added later. It also does not show any shares)
  
 
  [global]
 
  [global]
        security = ADS
+
    workgroup = SAMDOM
        workgroup = SAMDOM
+
    security = ADS
        realm = SAMDOM.EXAMPLE.COM
+
    realm = SAMDOM.EXAMPLE.COM
 
   
 
   
        log file = /var/log/samba/%m.log
+
    winbind refresh tickets = Yes
        log level = 1
+
    vfs objects = acl_xattr
+
    map acl inherit = Yes
        # Default ID mapping configuration for local BUILTIN accounts
+
    store dos attributes = Yes
        # and groups on a domain member. The default (*) domain:
+
 
        # - must not overlap with any domain ID mapping configuration!
+
 
        # - must use a read-write-enabled back end, such as <code>tdb</code>.
+
If you are creating a new smb.conf on an unjoined machine and add these lines, a keytab will be created during the join:
        # - Adding just this is not enough
+
    dedicated keytab file = /etc/krb5.keytab
        # - You must set a DOMAIN backend configuration, see below
+
    kerberos method = secrets and keytab
        idmap config * : backend = tdb
+
 
        idmap config * : range = 3000-7999
+
 
 +
If you do not want to enter the domain set in '<code>workgroup =</code>' during login etc (just 'username' instead of DOMAIN\username), add this line:
 +
    winbind use default domain = yes
 +
{{Imbox
 +
| type = note
 +
| text = This will only work for the default domain. For any other domains, you must use 'DOMAIN\username'.
 +
}}
 +
 
 +
 
 +
For testing purposes only (remove for production), add these lines:
 +
    winbind enum users = yes
 +
    winbind enum groups = yes
 +
 
 +
{{Imbox
 +
| type = note
 +
| text = The above lines just make 'getent passwd' and 'getent group' display all domain users and groups, they are not required for anything else and Samba will work correctly and faster without them.
 +
}}
 +
 
 +
 
 +
To disable printing completely, add these lines:
 +
    load printers = no
 +
    printing = bsd
 +
    printcap name = /dev/null
 +
    disable spoolss = yes
 +
 
 +
 
 +
'''You now need to add the 'idmap config' lines for your preferred winbind method.'''
 +
 
  
:For information on the parameters, see the <code>smb.conf(5)</code> man page.
+
== Choose backend for id mapping in winbindd ==
  
* '''You must add an ID mapping configuration, for each domain that you want Samba to be aware of, to the <code>[global]</code> section of your <code>smb.conf</code> file.'''
+
'''Select one of the following hyperlinks to find information about the relevant Samba domain back end and what <code>idmap config</code> lines to add:'''
* '''You must click on one of the following hyperlinks to find information about the Samba domain back ends:'''
 
  
 
:{| class="wikitable"
 
:{| class="wikitable"
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|'''[[Idmap_config_autorid|idmap config autorid]]'''
 
|'''[[Idmap_config_autorid|idmap config autorid]]'''
 
|<code>idmap_autorid(8)</code>
 
|<code>idmap_autorid(8)</code>
|-
 
|<code>hash</code>
 
|[[Idmap_config_hash|idmap config hash]]
 
|<code>idmap_hash(8)</code>
 
|-
 
|<code>ldap</code>
 
|[[Idmap_config_ldap|idmap config ldap]]
 
|<code>idmap_ldap(8)</code>
 
|-
 
|<code>nss</code>
 
|[[Idmap_config_nss|idmap config nss]]
 
|<code>idmap_nss(8)</code>
 
 
|}
 
|}
  
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{{Imbox
 
{{Imbox
 
| type = note
 
| type = note
| text = Mapping the domain administrator to the local <code>root</code> account is optional. Only configure the mapping if the domain administrator must be able to execute file operations on the domain member using <code>root</code> permissions. You should be aware that mapping Administrator to the <code>root</code> account will not allow you to log onto Unix domain members as <code>Administrator</code>.  
+
| text = You can optionally map the domain Administrator account to the local <code>root</code> account on a Unix domain member. Configuring the mapping allows the domain Administrator to execute file operations as <code>root</code> on the Unix domain member. If you do map Administrator to the <code>root</code> account, Administrator will be unknown to the OS and will not be able to log onto a Unix domain member. Only follow the method below to map <code>Administrator</code> to <code>root</code>, never give Administrator a <code>uidNumber</code> attribute, doing this will break the default Administrator mapping on a Samba AD DC.  
 
}}
 
}}
  
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:{{Imbox
 
:{{Imbox
 
| type = important
 
| type = important
| text = When using the <code>ad</code> ID mapping back end, do not set the <code>uidNumber</code> attribute for the domain administrator account. If the account has the attribute set, the value overrides the local UID <code>0</code> of the <code>root</code> user and thus the mapping fails.
+
| text = When using the <code>ad</code> ID mapping back end, never set a <code>uidNumber</code> attribute for the domain Administrator account. If the account has the attribute set, the value will override the local UID <code>0</code> of the <code>root</code> user on Samba AD DC's and thus the mapping fails.
 
}}
 
}}
  
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:* Do not add the <code>winbind</code> entry to the NSS <code>shadow</code> database. This can cause the <code>wbinfo</code> utility fail.
 
:* Do not add the <code>winbind</code> entry to the NSS <code>shadow</code> database. This can cause the <code>wbinfo</code> utility fail.
 +
 +
:{{Imbox
 +
| type = note
 +
| text = If there's a line containing an <code>initgroups</code> directive, add <code> [success=continue] winbind</code>, otherwise the NSS library will not ask winbindd for a user's additional group memberships. Do not add the <code>initgroups</code> line if it does not exist.
 +
}}
  
 
:{{Imbox
 
:{{Imbox
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}}
 
}}
  
* If you compiled Samba, add symbolic links from the <code>libnss_winbind</code> library to the operating system's library path. For details, see [[Libnss_winbind_Links|libnss_winbind Links]]. If you used packages to install Samba, the link is usually created automatically.
+
:{{Imbox
 
+
| type = note
 +
| text = If you compiled Samba, add symbolic links from the <code>libnss_winbind</code> library to the operating system's library path. For details, see [[Libnss_winbind_Links|libnss_winbind Links]]. If you used packages to install Samba, the link is usually created automatically.
 +
}}
  
 +
= Starting the Services =
  
 +
Start the following services to have a fully functioning Unix domain member:
  
 +
* The <code>smbd</code> service
 +
 +
* The <code>nmbd</code> service
  
= Starting the Services =
+
* The <code>winbindd</code> service
  
To start the services on a domain member:
 
  
* Start the <code>winbindd</code> service to enable the name service switch (NSS) library to look up domain users and groups:
+
:{{Imbox
 +
| type = note
 +
| text = If you do not require Network Browsing, you do not need to start the <code>nmbd</code> service on a Unix domain member.
 +
}}
  
# winbindd
 
 
* If you set up file shares or printer services on the domain member, additionally start the <code>smbd</code> and <code>nmbd</code> service:
 
 
# smbd
 
# nmbd
 
  
 
:{{Imbox
 
:{{Imbox
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| text = You must not start the <code>samba</code> service on a domain member. This service is required only on Active Directory (AD) domain controllers (DC).
 
| text = You must not start the <code>samba</code> service on a domain member. This service is required only on Active Directory (AD) domain controllers (DC).
 
}}
 
}}
 +
  
 
Samba does not provide System V init scripts, <code>systemd</code>, <code>upstart</code>, or service files for other init services.
 
Samba does not provide System V init scripts, <code>systemd</code>, <code>upstart</code>, or service files for other init services.

Latest revision as of 09:13, 12 November 2019

Introduction

A Samba domain member is a Linux machine joined to a domain that is running Samba and does not provide domain services, such as an NT4 primary domain controller (PDC) or Active Directory (AD) domain controller (DC).

On a Samba domain member, you can:

  • Use domain users and groups in local ACLs on files and directories.
  • Set up shares to act as a file server.
  • Set up printing services to act as a print server.
  • Configure PAM to enable domain users to log on locally or to authenticate to local installed services.

For details about setting up a Samba NT4 domain or Samba AD, see Domain Control.



Preparing the Installation

General Preparation

  • Verify that no Samba processes are running:
# ps ax | egrep "samba|smbd|nmbd|winbindd"
If the output lists any samba, smbd, nmbd, or winbindd processes, shut down the processes.
  • If you previously run a Samba installation on this host:
  • Backup the existing smb.conf file. To list the path to the file, enter:
# smbd -b | grep "CONFIGFILE"
   CONFIGFILE: /usr/local/samba/etc/samba/smb.conf
  • Remove all Samba database files, such as *.tdb and *.ldb files. To list the folders containing Samba databases:
# smbd -b | egrep "LOCKDIR|STATEDIR|CACHEDIR|PRIVATE_DIR"
  LOCKDIR: /usr/local/samba/var/lock/
  STATEDIR: /usr/local/samba/var/locks/
  CACHEDIR: /usr/local/samba/var/cache/
  PRIVATE_DIR: /usr/local/samba/private/
Starting with a clean environment helps you to prevent confusion, and no files from your previous Samba installation are mixed with your new domain member installation.


Preparing a Domain Member to Join an Active Directory Domain

Configuring DNS

Active Directory (AD) uses DNS in the background, to locate other DCs and services, such as Kerberos. Thus AD domain members and servers must be able to resolve the AD DNS zones.

The following describes how to manually configure Linux clients to use DNS servers. If you are running a DHCP server providing DNS settings to your client computers, configure your DHCP server to send the IP addresses of your DNS servers.

Configuring the /etc/resolv.conf

Set the DNS server IP and AD DNS domain in your /etc/resolv.conf. For example:

nameserver 10.99.0.1
search samdom.example.com

Some utilities, such as NetworkManager can overwrite manual changes in that file. See your distribution's documentation for information about how to configure name resolution permanently.



Testing DNS resolution

To verify that your DNS settings are correct and your client or server is able to resolve IP addresses and host names use the nslookup command. The command is available on Linux and Windows.



Forward Lookup

To resolve a host name its IP address:

# nslookup DC1.samdom.example.com
Server:         10.99.0.1
Address:        10.99.0.1#53

Name:   DC1.samdom.example.com
Address: 10.99.0.1



Reverse Lookup

To resolve a IP address to its host name:

# nslookup 10.99.0.1
Server:        10.99.0.1
Address:	10.99.0.1#53

1.0.99.10.in-addr.arpa	name = DC1.samdom.example.com.

Note that in a Samba AD, the reverse zone is not automatically configured. To set up a reverse zone, see DNS Administration.



Resolving SRV Records

Active Directory (AD) uses SRV records to locate services, such as Kerberos and LDAP. To verify that SRV records are resolved correctly, use the nslookup interactive shell:

# nslookup
Default Server:  10.99.0.1
Address:  10.99.0.1

> set type=SRV
> _ldap._tcp.samdom.example.com.
Server:  UnKnown
Address:  10.99.0.1

_ldap._tcp.samdom.example.com   SRV service location:
          priority       = 0
          weight         = 100
          port           = 389
          svr hostname   = dc1.samdom.example.com
samdom.example.com      nameserver = dc1.samdom.example.com
dc1.samdom.example.com  internet address = 10.99.0.1 



Error Messages

  • The DNS server is not able to resolve the host name:
** server can't find DC1.samdom.example.com: NXDOMAIN
  • The DNS server is not able to resolve the IP address:
** server can't find 1.0.99.10.in-addr.arpa: NXDOMAIN
  • The DNS server used is not available:
;; connection timed out; no servers could be reached






Configuring Kerberos

Samba supports Heimdal and MIT Kerberos back ends. To configure Kerberos on the domain member, set the following in your /etc/krb5.conf file:

[libdefaults]
	default_realm = SAMDOM.EXAMPLE.COM
	dns_lookup_realm = false
	dns_lookup_kdc = true

The previous example configures Kerberos for the SAMDOM.EXAMPLE.COM realm.

The Samba teams recommends to no set any further parameters in the /etc/krb5.conf file.

If your /etc/krb5.conf contains an include line it will not work, you Must remove this line.



Configuring Time Synchronisation

Kerberos requires a synchronised time on all domain members. Thus it is recommended to set up an NTP client. For further details, see Configuring Time Synchronisation on a Unix Domain Member.



Local Host Name Resolution

When you join the host to the domain, Samba tries to register the host name in the AD DNS zone. For this, the net utility must be able to resolve the host name using DNS or using a correct entry in the /etc/hosts file.

To verify that your host name resolves correctly, use the getent hosts command. For example:

# getent hosts M1
10.99.0.5      M1.samdom.example.com    M1

The host name and FQDN must not resolve to the 127.0.0.1 IP address or any other IP address other than the one used on the LAN interface of the domain member.

If no output is displayed or the host is resolved to the wrong IP address and you are not using dhcp, set the correct entry in the /etc/hosts file. For example:

127.0.0.1      localhost
10.99.0.5      M1.samdom.example.com    M1

If you are using dhcp, check that /etc/hosts only contains the '127.0.0.1' line shown above. If you continue to have problems, contact the sysadmin who controls your DHCP server.

  • On debian related systems you will also see the line 127.0.1.1 hostname in /etc/hosts, remove it before you install samba.
  • Please keep the line : 127.0.0.1 localhost

if you need to add aliases to the machine hostname, add them to the end of the line that starts with the machines ipaddress, not the 127.0.0.1 line.



Preparing a Domain Member to Join an NT4 Domain

For joining a host to an NT4 domain, no preparation is required.



Installing Samba

For details, see Installing Samba.



Configuring Samba

Setting up a Basic smb.conf File

When Setting up smb.conf on a Unix domain member, you will need to make a few decisions.

  • Do you require users and groups to have the same IDs everywhere, including Samba AD DCs ?
  • Do you only want your users and groups to have the same IDs on Unix domain members ?

After making your decision, you will have another decision to make, this decision could affect what you think you have already decided.

  • Do you want or need individual users to have different login shells and/or Unix home directory paths ?

If you need your users to have different login shells and/or Unix home directory paths, or you want them to have the same ID everywhere, you will need to use the winbind 'ad' backend and add RFC2307 attributes to AD.



If your users will only use the Samba AD DC for authentication and will not store data on it or log into it, you can use the the winbind 'rid' backend, this calculates the user and group IDs from the Windows RID, if you use the same [global] section of the smb.conf on every Unix domain member, you will get the same IDs. If you use the 'rid' backend you do not need to add anything to AD and in fact, any RFC2307 attributes will be ignored. When using the 'rid' backend you must set the 'template shell' and 'template homedir' parameters in smb.conf, these are global settings and everyone gets the same login shell and Unix home directory path, unlike the RFC2307 attributes where you can set individual Unix home directory paths and shells.

There is another way of setting up Samba, this is where you require your users and groups to have the same ID everywhere, but only need your users to have the same login shell and use the same Unix home directory path. You can do this by using the winbind 'ad' backend and using the template lines in smb.conf. This way you only have to add uidNumber & gidNumbers attributes to AD.

Having decided which winbind backend to use, you now have a further decision to make, the ranges to use with 'idmap config' in smb.conf. By default on a Unix domain member, there are multiple blocks of users & groups:

  • The local system users & groups: These will be from 0-999
  • The local Unix users and groups: These start at 1000
  • The 'well Known SIDs':  ????
  • The DOMAIN users and groups: ADUC, by default, starts these at 10000
  • Trusted domains:  ????
  • Anything that isn't a 'well Known SID' or a member of DOMAIN or a trusted domain: ????


As you can see from the above, you shouldn't set either the '*' or 'DOMAIN' ranges to start at 999 or less, as they would interfere with the local system users & groups. You also should leave a space for any local Unix users & groups, so starting the 'idmap config' ranges at 3000 seems to be a good compromise.

You need to decide how large your 'DOMAIN' is likely to grow to and you also need to know if you have any trusted domains or if you may need to have any in future.

Bearing the above information in mind, you could set the 'idmap config' ranges to the following:

Domain Range
* 3000-7999
DOMAIN 10000-999999

You could also have any trusted domains starting at:

Domain Range
TRUSTED 1000000-9999999

If you set the '*' range above the 'DOMAIN' range, the ranges will conflict if the 'Domain' grows to the point that the next ID would be the same as the '*' range start ID.

With the above suggested ranges, no range will overlap or interfere with another.

You may also have seen examples of the '*' range being used for everything, this is not recommended and should not be used.


Before joining the domain, configure the domain member's smb.conf file:

  • To locate the file, enter:
# smbd  -b | grep CONFIGFILE
  CONFIGFILE: /usr/local/samba/etc/smb.conf

To create a basic smb.conf, you need something like this (note, this does not include any 'idmap config' auth lines, they will be added later. It also does not show any shares)

[global]
   workgroup = SAMDOM
   security = ADS
   realm = SAMDOM.EXAMPLE.COM

   winbind refresh tickets = Yes
   vfs objects = acl_xattr
   map acl inherit = Yes
   store dos attributes = Yes


If you are creating a new smb.conf on an unjoined machine and add these lines, a keytab will be created during the join:

   dedicated keytab file = /etc/krb5.keytab
   kerberos method = secrets and keytab


If you do not want to enter the domain set in 'workgroup =' during login etc (just 'username' instead of DOMAIN\username), add this line:

   winbind use default domain = yes


For testing purposes only (remove for production), add these lines:

   winbind enum users = yes
   winbind enum groups = yes


To disable printing completely, add these lines:

   load printers = no
   printing = bsd
   printcap name = /dev/null
   disable spoolss = yes


You now need to add the 'idmap config' lines for your preferred winbind method.


Choose backend for id mapping in winbindd

Select one of the following hyperlinks to find information about the relevant Samba domain back end and what idmap config lines to add:

Back End Documentation Man Page
ad idmap config ad idmap_ad(8)
rid idmap config rid idmap_rid(8)
autorid idmap config autorid idmap_autorid(8)


Mapping the Domain Administrator Account to the Local root User

Samba enables you to map domain accounts to a local account. Use this feature to execute file operations on the domain member's file system as a different user than the account that requested the operation on the client.

To map the domain administrator to the local root account:

  • Add the following parameter to the [global] section of your smb.conf file:
username map = /usr/local/samba/etc/user.map
  • Create the /usr/local/samba/etc/user.map file with the following content:
!root = SAMDOM\Administrator

For further details, see username map parameter in the smb.conf(5) man page.



Joining the Domain

  • To join the host to an Active Directory (AD), enter:
# net ads join -U administrator
Enter administrator's password: Passw0rd
Using short domain name -- SAMDOM
Joined 'M1' to dns domain 'samdom.example.com'
  • To join the host to an NT4 domain, enter:
# net rpc join -U administrator
Enter administrator's password: Passw0rd
Joined domain SAMDOM.

If you have problems joining the domain, check your configuration. For further help, see Troubleshooting Samba Domain Members.



Configuring the Name Service Switch

To enable the name service switch (NSS) library to make domain users and groups available to the local system:

  • Append the winbind entry to the following databases in the /etc/nsswitch.conf file:
passwd: files winbind
group:  files winbind
  • Keep the files entry as first source for both databases. This enables NSS to look up domain users and groups from the /etc/passwd and /etc/group files before querying the Winbind service.
  • Do not add the winbind entry to the NSS shadow database. This can cause the wbinfo utility fail.

Starting the Services

Start the following services to have a fully functioning Unix domain member:

  • The smbd service
  • The nmbd service
  • The winbindd service




Samba does not provide System V init scripts, systemd, upstart, or service files for other init services.

  • If you installed Samba using packages, use the script or service configuration file provided by the package to start Samba.
  • If you built Samba, see your distribution's documentation for how to create a script or configuration to start services.



Testing the Winbindd Connectivity

Sending a Winbindd Ping

To verify if the Winbindd service is able to connect to Active Directory (AD) Domain Controllers (DC) or a primary domain controller (PDC), enter:

# wbinfo --ping-dc
checking the NETLOGON for domain[SAMDOM] dc connection to "DC.SAMDOM.EXAMPLE.COM" succeeded

If the previous command fails, verify:

  • That the winbindd service is running.
  • Your smb.conf file is set up correctly.


Using Domain Accounts and Groups in Operating System Commands

Looking up Domain Users and Groups

The libnss_winbind library enables you to look up domain users and groups. For example:

  • To look up the domain user SAMDOM\demo01:
# getent passwd SAMDOM\\demo01
SAMDOM\demo01:*:10000:10000:demo01:/home/demo01:/bin/bash
  • To look up the domain group Domain Users:
# getent group "SAMDOM\\Domain Users"
SAMDOM\domain users:x:10000:


Assigning File Permissions to Domain Users and Groups

The name service switch (NSS) library enables you to use domain user accounts and groups in commands. For example to set the owner of a file to the demo01 domain user and the group to the Domain Users domain group, enter:

# chown "SAMDOM\\demo01:SAMDOM\\domain users" file.txt



Setting up Additional Services on the Domain Member

On a Samba domain member, you can additionally set up:



Troubleshooting

For details, see Troubleshooting Samba Domain Members.