1. What
is Samba and explain it?
(i) An open source implementation of the SMB file sharing protocolthat provides file and print services to SMB/CIFS clients. Samba allows a non-Windows server to
communicate with the same networking protocol as the Windows products.
(ii) Samba
allows Linux computers to share files and printers across a network connection
by using SMB protocol. Samba
will support DFS, NFS, ufs
file systems to share files and directories. That's why Samba
is used to share files and directories between different
platforms.
(iii) Samba will support printer sharing and it
requires authentication.
2. What
are the differences between Samba and
NFS?
(i) Samba
supports to all O/S platforms, whereas
NFS will support the same platforms only.
(ii) There
is a security in Samba because Samba
requires authentication, whereas in NFS there is no security if there
is no kerberos because NFS does not requires
authentication.
(iii) Samba
will support printer sharing,
whereas NFS will not support printer sharing.
3. What
are the different file systems for sharing different O/S?
(i) Windows ---
Windows -----> Distributed
File system (DFS)
(ii) Linux --- Linux
-----> Network File
system (NFS)
(iii) Unix --- Unix
-----> Network File
system (NFS)
(iv) Apple MAC
--- Apple MACs
-----> Apple File sharing
Protocol (AFP)
(v) Windows ---
Linux -----> Common
Internet File system
(CIFS)
4. What
are the requirements or what is the profile of Samba?
(i) Packages : samba* for
samba server and samba-client*
for samba client
(ii) Deamons : smbd and
nmbd for RHEL - 6
where as smbd is for Samba server deamon and nmbd
is for Netbios service deamon.
smb and
nmb for RHEL - 7
where as smb is for Samba server deamon and
nmb is for Netbios service deamon.
(iii) Scripting files : /etc/init.d/smb and
/etc/init.d/nmb
(iv) Port
number : 137
---> to verify the share
name, 138 --->
to data transfer,
139 --->
to connection establish and 445
---> for authentication
(v) Log file : /var/log/samba
(vi)
Configuration : /etc/samba/smb.conf
(vii) File
systems : CIFS
(Common Internet File system)
5. How to configure the Samba
server?
(i) Install the
samba package by # yum
install samba* -y
command.
(ii) Create a
samba shared directory by # mkdir
/samba command.
(iii) Modify the
permissions of the above samba shared directory.
# chmod
777 /samba
(iv) Modify the
SELinux context of the samba directory if SELinux is enabled.
# chcon
-t samba_share_t /samba
(v) Create the
samba user and assign the password for the samba user.
# useradd raju (to
create the samba user)
# smbpasswd -a
raju (to assign the samba password for the user
raju)
(vi) Assign the ACL
permissions (like read,
write and execute) to the above shared directory if it is
necessary.
# setfacl
-m u : :
rwx
Example : # setfacl -m
u:raju:rwx /samba
(vii) Open the
samba configuration file and put an entries of the Samba configuration.
# vim
/etc/samba/smb.conf
Go
to last line and copy the last 7 lines
and paste them at last. And then
modify as below.
[samba] (this
is the samba shared name)
comment
= public stuff (this
is a comment for samba)
path
= /samba (share
directory name with full path) public = yes (means no authentication)
= no (means
requires authentication)
writable
= yes (in
read-write mode)
=
no (in
read only mode)
printable
= no (printing
is not available)
= yes (printing
is available)
write
list = raju (to
give the write permission to user raju)
= + (to give the write permission to the
group)
valid
users = raju, u2 or @group 1, @group 2 (to
give the authentication to the users or
groups)
hosts
allow = IP 1 or IP 2
or host 1 or
host2 or or
(to
share the
directory to IP 1 or IP 2
or host 1 or
host2)
work
group = (to
share the directory to the windows work group)
create
mask = 644 (the files created by samba users
with 644 permission)
directory
mask = 744 or 755 (the directories created by samba users
with 744
or 755 permissions)
(save and
exit the configuration
file)
(viii)
Verify the configuration file for
syntax errors by # testparm command.
(ix) Restart the
samba deamons in RHEL - 6 and RHEL - 7.
# service
smbd nmbd restart (to
restart the samba services in RHEL - 6)
# chkconfig
smbd nmbd on (to enable the samba services at next
boot in
RHEL - 6)
# systemctl
restart smb nmb (to
restart the samba services in RHEL - 7)
# systemctl
enable smb nmb (to enable the samba services at next
boot in
RHEL - 7)
(x) Add the samba
service to IP tables and
Firewall.
# setup (then select Firewall
configuration option to add the service to IP tables in
RHEL - 6)
# service
iptables restart (to restart the IP tables
in RHEL - 6)
# firewall-cmd --permanent
--add-service=samba (to add the samba service to firewall in
RHEL - 7)
# firewall-cmd
--complete-reload (to reload the firewall in RHEL - 7)
6. How to access the samba share
directory at client side?
(i) Install client side
samba packages by #
yum install samba-client* cifs-utils -y
command.
(ii) Check the samba shared directory
names from client side.
# smbclient -L
// (then it will ask password, here don't
enter any password because it does not require
any password)
Example :# smbclient -L
//server9.example.com or 172.25.9.11
(iii) connect the samba server
with user credentials and access the samba shared directory.
# smbclient /// -U
(Where U is
Capital Letter and we
have to enter the user's samba password)
Example : # smbclient //server9.example.com/samba -U
raju (then smb :/>
prompt appears)
smb:/> ls (to
see the contents of the samba shared directory)
smb:/> pwd (to
see the present working directory)
smb:/> ! ls (to
see the client's local directory
contents)
smb:/>
get (to
download the specified file from samba server)
smb:/> mget
... (to download multiple files from samba server)
smb:/> put
(to
upload the specified file to the samba server)
smb:/> put
... (to upload multiple files to the
samba server)
smb:/> exit (to
exit from the samba server)
7. How to mount the samba shared
directory permanently?
(i) Create the mount point for the samba
shared directory.
# mkdir
/mnt/samba
(ii) Put an entry of the mount point
details in /etc/fstab file.
# vim
/etc/fstab
/// cifs
defaults , username=,
password= 0 0
Example
: //server9.example.com/samba /mnt/samba cifs
defaults, username=raju, password= 0 0 (save
and exit this
file)
(iii) Mount all
the mount points which are having entries in
/etc/fstab file.
# mount -a
(iv) Check all
the mount points by #
df -hT command.
8. How to mount the samba shared
directory using credential file?
(i) Create one file and put an entries of the user name
and password details.
# vim
/root/smbuser
username=raju
password= (save
and exit the
file)
(ii) Open
/etc/fstab file and
put an entries of the above credential details of user.
# vim
/etc/fstab
//server9.example.com/samba /mnt/samba cifs
credentials=/root/smbuser,
multiuser, sec=ntlmssp 0
0
(save and
exit this file)
9. How to access the samba share
directory if it already mounted?
(i) Go to Client system and switch to
samba user.
# su
- raju
$
cd /mnt/samba
$
ls (permission
denied message will be displayed)
$ cifscreds add
$ ls (to
see the contents of the samba shared directory)
10. How to access the samba server
from windows system?
(i) Goto Windows
system, click on START
button, click on Run
and type as \\172.25.9.11\samba command.
(ii) Then provide
samba user name and password
if it prompts us.
(iii) Then see
the contents of the samba shared directory.
Other useful
commands :
# smbpasswd -a
(to
add the samba password to the samba user)
# smbpasswd -d
(to disable the samba
user's password)
# smbpasswd -e
(to enable the samba user's password)
# smbpasswd -r
(to remove the samba user's password)
# smbpasswd -x
(to delete the samba user's password)
# smbpasswd -n
(to set the samba user's password as
null)
# findsmb (to check how many samba servers are
running in our network)
# pdbedit (to check the available samba users who
are accessing currently)
# smbstatus (to check how many smb clients are
connected to the samba server)
# mount -t
cifs /// -o
user= (to mount the samba share directory on
local mount point temporarily)
Example : # mount
-t cifs //172.25.9.11/samba /mnt/samba -o
user=raju
17. NTP (Network Time Protocol) or
Chrony
1. What is NTP
and Chrony?
NTP stands for
Network Time Protocol in RHEL - 6 and
Chrony is also a Network Time Protocol in RHEL - 7. These
are used to synchronize the time on your Linux system with a centralized NTP or
Chrony server.A local NTP
or
Chrony server on the network can be synchronized with an external timing
source to keep all the servers
in your organization in-sync with an accurate time.
2. What are the differences
between NTP and
Chrony?
|
NTP
|
Chrony
|
|
This is used in RHEL - 6.
|
This is used in RHEL - 7.
|
|
Package is ntp
or system-config-date.
|
Package is chrony.
|
|
It's deamon is ntpd and
Port number is 123.
|
It's deamon is chronyd and
Port number is 123.
|
|
We have to install the package manually.
|
By default this package is installed.
|
|
#
ntpq -p (to check
ntp is configured or not).
|
#
chronyc sources -v
(to check chrony is
configured or not).
|
|
Configuration file is /etc/ntp.conf
|
Configuration file is /etc/chrony.conf
|
|
Log file is /var/log/ntpstat
|
Log file is /var/log/chrony
|
3. How to configure the NTP
and Chrony client?
NTP :
(i) Install the ntp
package by # yum install ntp*
-y or # yum install
system-config-date* -y command.
(ii) open the configuration file by # system-config-date or
# vim /etc/ntp.conf command.
(#
system-config-date command is used to
configure the NTP in graphical mode)
* Make a comment on line numbers
21, 22 and
23. Then go to line number 24 and
type as below.
server
Example : server
classroom.example.com
(iii) Restart the ntpd
service by # service ntpd restart
command.
(iv) Enable
the ntp
service at next boot by #
chkconfig ntpd on
command.
(v) Check whether
the NTP
is configured or not by #
ntpq -p command.
Chrony :
(i) Chrony package is not installed because by default
it is installed. If it not installed then install the package by #
yum install chrony*
-y command.
(ii) Open the chrony configuration file
by #
vim /etc/chrony.conf command.
* Make a comment on line numbers 3, 4
and 5. Then go to line number 6
and type as below.
server
iburst (save and
exit this file)
Example : server
classroom.example.com iburst
(iii) Restart the chrony
service by # systemctl restart chronyd
command.
(iv) Enable
the chrony service at next boot by #
systemctl enable chronyd
command.
(v) Check whether the Chrony
is configured or not by
# chronyc sources
-v command.
# timedatectl (to check whether the
client's time is synchronized to the
server's time)
# timedatectl list-timezones (to list the
different time zones)
# timedatectl set-time
# timedatectl set-timezone Asia/Kolkata (to set the time zone in RHEL
- 7)
# tzselect Asia/Kolkata (to set the time
zone in RHEL - 6)
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