Date Created: Wed 22-Sep-2010

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Preparing and Installing ClearCase for use on Windows interop workgroup with Linux

ClearCase Workgroup (user mode) pre-requisites

This document is part of a complete set-up of installing and configuring a Windows interop environment with Linux on RHEL 5. There is not another set of detailed documents anywhere on the internet out side of our site. If this article does not contain enough information, search the rest of this site: and you will find many mini articles on Linux and Windows interop and MVFS/Samba support. Also feel free to contact me if you require ClearCase consulting and support.

The approach for this ClearCase setup is to have all users, groups and computers reside in a single domain. Below are some immediate reading points to explain the prerequisite tables.

· It is recommended that all users of the Windows system must have an equivalent Linux account with the same username and same case otherwise. The case and spelling must be identical between the operating systems for both the usernames and primary groups. Avoid names that have spaces or special characters that are not supported on the different operating systems.

· It is mandatory that the primary group on Linux/UNIX and Windows match.

· Rational strongly recommends that you limit your group name to 8 characters or less AND recommends that group names do not contain spaces. This is due to the fact that ClearCase on Linux/UNIX is compiled for POSIX compliance. Rational support has seen instances where groups containing more than 8 characters such as “clearcase_users” will work for a period of time; however, once these groups stop working due to group name truncation during a look-up, it is impossible to resolve the issue.

· When the User Security Mode is utilized, all of the user, group and machine accounts are stored on a the Windows clients and in Linux and mapped via the Samaba user map.

Security groups

The following active directory security groups are to be created all within the same OU in Active Directory

User group Description
ccadm ClearCase administrator group for administrators and albd account
ccusr1, ccusr2, ccuser3, ccusr4,ccusr5 ClearCase user groups.

Only ccusr 1 is required for now. The other user groups can be added later on if security to restrict access to VOBs is required


The following user accounts and group memberships are required.

Account Password to be set Group membership required Description
cc_albd Password123 ccadm ClearCase albd account that must be a member of ccadm
vobadmin Password123 ccadm, ccusr1 VOB administrator account that is a member of ccadm, ccusr
Single ClearCase accounts on Windows machine and Multiple accounts on the Linux machine. As required ccusr1 User accounts for each users using ClearCase on the Linux Server, so each Windows machine can map to a Linux user on Linux

· In order to use security = domain, the Samba server must be added to the Windows domain as a “domain member server”.

· On the Windows domain controller, add a machine account for the Samba server.

Install Clear case

Say no ..


The group I am using is ccusr1 which is a local (non-domain_ account, it is local on This Windows machine, which is not joined to a domain and the Linux server also uses this group as the primary group.

Restart Windows machine.


I then also added my user account called user to ccusr1 as this is what group my view and vob has on on Linux box.

Note If the Linux server running ClearCase and Samba has been part of a domain, delete the computer account as it might be joined to the domain and we do not want that. We want it to be part of a workgroup.

I also had to edit the smb.conf to chnage the workgroup t a name that was not the same as any widows domain name on the network

workgroup = samba


By using the smbclient as shown below you can see the workgroup is now samba and no master browser.

[root@clearcase ~]# smbclient -L localhost -N
Anonymous login successful
Domain=[SAMBA] OS=[Unix] Server=[Samba 3.2.13]

Sharename Type Comment
--------- ---- -------
tmp Disk Temporary file space
vobstore01 Disk
viewstore01 Disk
IPC$ IPC IPC Service (ClearCase Linux Server)
Anonymous login successful
Domain=[SAMBA] OS=[Unix] Server=[Samba 3.2.13]

Server Comment
--------- -------
CLEARCASE ClearCase Linux Server

Workgroup Master
--------- -------


I then removed active directory from my Windows 2003 server, so there was no PDC on my network. From now on I am going to use a VMWare machine for my PDC. This way I can just turn it off.


Below is the smb.conf fiel I used for this configuration

# This is the main Samba configuration file. You should read the
# smb.conf(5) manual page in order to understand the options listed
# here. Samba has a huge number of configurable options (perhaps too
# many!) most of which are not shown in this example
# For a step to step guide on installing, configuring and using samba,
# read the Samba-HOWTO-Collection. This may be obtained from:
# Many working examples of smb.conf files can be found in the
# Samba-Guide which is generated daily and can be downloaded from:
# Any line which starts with a ; (semi-colon) or a # (hash)
# is a comment and is ignored. In this example we will use a #
# for commentry and a ; for parts of the config file that you
# may wish to enable
# NOTE: Whenever you modify this file you should run the command "testparm"
# to check that you have not made any basic syntactic errors.
#======================= Global Settings =====================================
msdfs root = No
host msdfs = No
netbios name = clearcase
# workgroup = NT-Domain-Name or Workgroup-Name, eg: MIDEARTH
#workgroup = win2003.screv.local
workgroup = samba
# server string is the equivalent of the NT Description field
server string = ClearCase Linux Server

# Security mode. Defines in which mode Samba will operate. Possible
# values are share, user, server, domain and ads. Most people will want
# user level security. See the Samba-HOWTO-Collection for details.
security = user

# This option is important for security. It allows you to restrict
# connections to machines which are on your local network. The
# following example restricts access to two C class networks and
# the "loopback" interface. For more examples of the syntax see
# the smb.conf man page
; hosts allow = 192.168.1. 192.168.2. 127.

# If you want to automatically load your printer list rather
# than setting them up individually then you'll need this
; load printers = yes

# you may wish to override the location of the printcap file
; printcap name = /etc/printcap

# on SystemV system setting printcap name to lpstat should allow
# you to automatically obtain a printer list from the SystemV spool
# system
; printcap name = lpstat

# It should not be necessary to specify the print system type unless
# it is non-standard. Currently supported print systems include:
# bsd, cups, sysv, plp, lprng, aix, hpux, qnx
; printing = cups

# This option tells cups that the data has already been rasterized
cups options = raw

# Uncomment this if you want a guest account, you must add this to /etc/passwd
# otherwise the user "nobody" is used
; guest account = pcguest

# this tells Samba to use a separate log file for each machine
# that connects
log file = /var/log/samba/%m.log

# Put a capping on the size of the log files (in Kb).
max log size = 50

# Use password server option only with security = server
# The argument list may include:
# password server = My_PDC_Name [My_BDC_Name] [My_Next_BDC_Name]
# or to auto-locate the domain controller/s
;password server = *
;password server = hs001.win2003.screv.local

# Use the realm option only with security = ads
# Specifies the Active Directory realm the host is part of
;realm = win2003.screv.local

# Backend to store user information in. New installations should
# use either tdbsam or ldapsam. smbpasswd is available for backwards
# compatibility. tdbsam requires no further configuration.
; passdb backend = tdbsam

# Using the following line enables you to customise your configuration
# on a per machine basis. The %m gets replaced with the netbios name
# of the machine that is connecting.
# Note: Consider carefully the location in the configuration file of
# this line. The included file is read at that point.
; include = /usr/local/samba/lib/smb.conf.%m

# Configure Samba to use multiple interfaces
# If you have multiple network interfaces then you must list them
# here. See the man page for details.
; interfaces =

# Browser Control Options:
# set local master to no if you don't want Samba to become a master
# browser on your network. Otherwise the normal election rules apply
; local master = no

# OS Level determines the precedence of this server in master browser
# elections. The default value should be reasonable
; os level = 33

# Domain Master specifies Samba to be the Domain Master Browser. This
# allows Samba to collate browse lists between subnets. Don't use this
# if you already have a Windows NT domain controller doing this job
; domain master = yes

# Preferred Master causes Samba to force a local browser election on startup
# and gives it a slightly higher chance of winning the election
; preferred master = yes

# Enable this if you want Samba to be a domain logon server for
# Windows95 workstations.
; domain logons = yes

# if you enable domain logons then you may want a per-machine or
# per user logon script
# run a specific logon batch file per workstation (machine)
; logon script = %m.bat
# run a specific logon batch file per username
; logon script = %U.bat

# Where to store roving profiles (only for Win95 and WinNT)
# %L substitutes for this servers netbios name, %U is username
# You must uncomment the [Profiles] share below
; logon path = \\%L\Profiles\%U

# Windows Internet Name Serving Support Section:
# WINS Support - Tells the NMBD component of Samba to enable it's WINS Server
; wins support = yes

# WINS Server - Tells the NMBD components of Samba to be a WINS Client
# Note: Samba can be either a WINS Server, or a WINS Client, but NOT both
; wins server = w.x.y.z

# WINS Proxy - Tells Samba to answer name resolution queries on
# behalf of a non WINS capable client, for this to work there must be
# at least one WINS Server on the network. The default is NO.
; wins proxy = yes

# DNS Proxy - tells Samba whether or not to try to resolve NetBIOS names
# via DNS nslookups. The default is NO.
dns proxy = no

# These scripts are used on a domain controller or stand-alone
# machine to add or delete corresponding unix accounts
; add user script = /usr/sbin/useradd %u
; add group script = /usr/sbin/groupadd %g
; add machine script = /usr/sbin/adduser -n -g machines -c Machine -d /dev/null -s /bin/false %u
; delete user script = /usr/sbin/userdel %u
; delete user from group script = /usr/sbin/deluser %u %g
; delete group script = /usr/sbin/groupdel %g

#============================ Share Definitions ==============================
comment = Home Directories
browseable = no
writeable = yes

# Un-comment the following and create the netlogon directory for Domain Logons
; [netlogon]
; comment = Network Logon Service
; path = /usr/local/samba/lib/netlogon
; guest ok = yes
; writable = no
; share modes = no

# Un-comment the following to provide a specific roving profile share
# the default is to use the user's home directory
; path = /usr/local/samba/profiles
; browseable = no
; guest ok = yes

# NOTE: If you have a BSD-style print system there is no need to
# specifically define each individual printer
comment = All Printers
path = /usr/spool/samba
browseable = no
# Set public = yes to allow user 'guest account' to print
; guest ok = no
; writeable = no
printable = yes

# This one is useful for people to share files
comment = Temporary file space
path = /tmp
writeable = yes
guest ok = yes
public = yes
browseable = yes

# A publicly accessible directory, but read only, except for people in
# the "staff" group
; comment = Public Stuff
; path = /home/samba
; public = yes
; writable = yes
; printable = no
; write list = @staff

# Other examples.
# A private printer, usable only by fred. Spool data will be placed in fred's
# home directory. Note that fred must have write access to the spool directory,
# wherever it is.
; comment = Fred's Printer
; valid users = fred
; path = /homes/fred
; printer = freds_printer
; public = no
; writable = no
; printable = yes

# A private directory, usable only by fred. Note that fred requires write
# access to the directory.
; comment = Fred's Service
; path = /usr/somewhere/private
; valid users = fred
; public = no
; writable = yes
; printable = no

# a service which has a different directory for each machine that connects
# this allows you to tailor configurations to incoming machines. You could
# also use the %U option to tailor it by user name.
# The %m gets replaced with the machine name that is connecting.
; comment = PC Directories
; path = /usr/pc/%m
; public = no
; writable = yes

# A publicly accessible directory, read/write to all users. Note that all files
# created in the directory by users will be owned by the default user, so
# any user with access can delete any other user's files. Obviously this
# directory must be writable by the default user. Another user could of course
# be specified, in which case all files would be owned by that user instead.
; path = /usr/somewhere/else/public
; public = yes
; only guest = yes
; writable = yes
; printable = no

# The following two entries demonstrate how to share a directory so that two
# users can place files there that will be owned by the specific users. In this
# setup, the directory should be writable by both users and should have the
# sticky bit set on it to prevent abuse. Obviously this could be extended to
# as many users as required.
; comment = Mary's and Fred's stuff
; path = /usr/somewhere/shared
; valid users = mary fred
; public = no
; writable = yes
; printable = no
; create mask = 0765
path = /vobstore01
guest ok = yes
; guest only = no
writeable = yes
printable = no
; browseable = yes
path = /viewstore01
guest ok = yes
public = yes
only guest = no
writable = yes
printable = no

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