How to configure a Clustered Samba share using ctdb in Red Hat Cluster

NOTE: Red Hat Enterprise Linux 6 supports a maximum of four nodes running clustered Samba.

Course of action to be performed

• Create a multinode cluster(for this article I will be using 2 nodes)
• Create 2 logical volumes each for samba and ctdb in gfs2 format
• Create one partition for qdisk
• Start the cluster services
• Install Pre-requisite Packages
• Configure ctdb and samba
• Start ctdb services

....and you are all set
Overall pre-requisites (server)

• 1 server for openfiler (192.168.1.8)
• 2 servers for CentOS 6.5 (192.168.1.5 and 192.168.1.6)
• 1 server for Conga server (192.168.1.7)

Overall pre-requisites (rpms)

• High Availability Management (rpm group)
• High Availability (rpm group)
• iSCSI Storage Client (rpm group)
• gfs2-utils
• ctdb
• samba
• samba-client
• samba-winbind
• samba-winbind-clients

This was a brief overview of what we are going to perform but its going to take a while to reach the end of this course so lets start with creating our cluster

Creating 2 node cluster

For this article I am using CentOS 6.5 which is fully compatible with Red Hat so the packages and commands used here would be same as in Red Hat Linux.
Node 1: 192.168.1.5 (node1.example)
Node 2: 192.168.1.6 (node2.example)
Mgmt Node: 192.168.1.7 (node3.mgmt)
Openfiler: 192.168.1.8 (of.storage)

Use the above link to "Configure iSCSI Target using Openfiler"
Next continue to install the below packages on both the nodes

Add iSCSI targets using iSCSi initiator

Configure Logical Volume

[root@node2 ~]# fdisk /dev/sdc
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x36e0095b.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-10784, default 1): 1
Last cylinder, +cylinders or +size{K,M,G} (1-10784, default 10784):[Press Enter]
Using default value 10784
Command (m for help): p
Disk /dev/sdc: 11.3 GB, 11307843584 bytes
64 heads, 32 sectors/track, 10784 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x36e0095b
   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1       10784    11042800   83  Linux
Command (m for help): t
Selected partition 1
Hex code (type L to list codes): 8e
Changed system type of partition 1 to 8e (Linux LVM)
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.

[root@node2 ~]# partprobe /dev/sdc
Create 2 Logical Volume out of /dev/sdc1
[root@node2 ~]# pvcreate /dev/sdc1
  Physical volume "/dev/sdc1" successfully created
[root@node2 ~]# vgcreate samba_vg /dev/sdc1
  Volume group "samba_vg" successfully created
[root@node2 ~]# lvcreate -L 1G -n ctdb  samba_vg
  Logical volume "ctdb" created
[root@node2 ~]# lvcreate -L 9G -n samba  samba_vg
  Logical volume "samba" created

Configure GFS filesystem

[root@node2 mnt]# mkfs.gfs2 -p lock_dlm -t smbcluster:samba -j 2 /dev/samba_vg/samba
This will destroy any data on /dev/samba_vg/samba.
It appears to contain: symbolic link to `../dm-3'
Are you sure you want to proceed? [y/n] y
Device:                    /dev/samba_vg/samba
Blocksize:                 4096
Device Size                9.00 GB (2359296 blocks)
Filesystem Size:           9.00 GB (2359294 blocks)
Journals:                  2
Resource Groups:           36
Locking Protocol:          "lock_dlm"
Lock Table:                "smbcluster:samba"
UUID:                      062df74f-218a-bd22-34f8-ea58e7e3316a
[root@node2 mnt]# mkfs.gfs2 -p lock_dlm -t smbcluster:ctdb -j 2 /dev/samba_vg/ctdb
This will destroy any data on /dev/samba_vg/ctdb.
It appears to contain: symbolic link to `../dm-2'
Are you sure you want to proceed? [y/n] y
Device:                    /dev/samba_vg/ctdb
Blocksize:                 4096
Device Size                1.00 GB (262144 blocks)
Filesystem Size:           1.00 GB (262142 blocks)
Journals:                  2
Resource Groups:           4
Locking Protocol:          "lock_dlm"
Lock Table:                "smbcluster:ctdb"
UUID:                      8d243aeb-983b-9126-6678-47df6a2b93fe

Configure Quorum disk

NOTE: Perform this command on any one of the node and the same would be reflected on the other nodes also remember the label name used as you will have to use the same while configure qdisk for the cluster

Assign password to ricci

Update hosts file

Update your hosts file on all the nodes including management node

#node1
192.168.1.5     node1.example   node1
#node2
192.168.1.6     node2.example   node2
#node3
192.168.1.7     node3.mgmt      node3
#of
192.168.1.8     of.storage      of

Restart ricci services on both the nodes to reflect the new password

[root@node2 ~]# /etc/init.d/ricci start
Starting oddjobd:                                          [  OK  ]
generating SSL certificates...  done
Generating NSS database...  done
Starting ricci:                                            [  OK  ]

From here you will again have to follow the below article for the below steps
Configure Red Hat Cluster using VMware, Quorum Disk, GFS2, Openfiler

• Configuring a management node with conga
• Accessing luci console on browser
• Creating a Cluster using luci console
• Adding nodes to the cluster
• Configuring a qdisk
• Starting the cluster

Once all the above steps are successfully completed, verify your cluster state

Install and configure samba and ctdb

# yum -y install ctdb samba

Create respective directories for mounting the samba and ctdb on both the nodes

[root@node2 ~]# mkdir /mnt/ctdb
[root@node2 ~]# mkdir /mnt/samba
[root@node1 ~]# mkdir /mnt/samba
[root@node1 ~]# mkdir /mnt/ctdb

Add the below lines in /etc/fstab on all the nodes

/dev/samba_vg/samba     /mnt/samba              gfs2    defaults        0 0
/dev/samba_vg/ctdb      /mnt/ctdb               gfs2    defaults        0 0

Start gfs2 services on both the nodes to mount the respective share as specified in fstab file

[root@node2 ~]# service gfs2 start
Mounting GFS2 filesystem (/mnt/samba):                     [  OK  ]
Mounting GFS2 filesystem (/mnt/ctdb):                      [  OK  ]
[root@node1 ~]# service gfs2 start
Mounting GFS2 filesystem (/mnt/samba):                     [  OK  ]
Mounting GFS2 filesystem (/mnt/ctdb):                      [  OK  ]

Add the below entry in smb.conf of all the nodes

# vi /etc/samba/smb.conf
[global]
        guest ok = yes
        clustering = yes
        netbios name = example
[profiles]
        path = /profiles
        share modes = yes
        guest only = yes
        browseable = yes
        writable = yes
        guest ok = yes
        create mode = 0777
        directory mode = 0777
        ea support = yes

Create the share path as mentioned in smb.conf for all the nodes

# mkdir /profiles

Configure CTDB

Pre-requisites:
Mount the cluster filesystem on all the linux boxes that will form your cluster.
The CTDB configuration file is located at /etc/sysconfig/ctdb. The mandatory fields that must be configured for CTDB operation are as follows:
CTDB_NODES
CTDB_PUBLIC_ADDRESSES
CTDB_RECOVERY_LOCK
CTDB_MANAGES_SAMBA (must be enabled)
CTDB_MANAGES_WINBIND (must be enabled if running on a member server)

# vi /etc/sysconfig/ctdb
CTDB_RECOVERY_LOCK="/mnt/ctdb/.ctdb.lock"
CTDB_NODES=/etc/ctdb/nodes
CTDB_PUBLIC_ADDRESSES=/etc/ctdb/public_addresses
CTDB_MANAGES_SAMBA=yes
CTDB_MANAGES_WINBIND=yes
CTDB_NODES

This should be a private non-routable subnet which is only used for internal cluster traffic. This file must be the same on all nodes in the cluster.
Make sure that these IP addresses are automatically started when the cluster node boots and that each node can ping each other node, as in the following example(on all the nodes):

192.168.1.5
192.168.1.6

CTDB_PUBLIC_ADDRESSES

[root@node1 ~] vi /etc/ctdb/public_addresses
192.168.1.4/24 eth2
192.168.1.7/24 eth2
[root@node2 ~] vi /etc/ctdb/public_addresses
192.168.1.4/24 eth0
192.168.1.7/24 eth0

CTDB_RECOVERY_LOCK

Testing ctdb

•  ctdb status
•  ctdb ip
•  ctdb ping

[root@node1 ~]# ctdb status
Number of nodes:2
pnn:0 192.168.1.5      OK (THIS NODE)
pnn:1 192.168.1.6      OK
Generation:1976870623
Size:2
hash:0 lmaster:0
hash:1 lmaster:1
Recovery mode:NORMAL (0)
Recovery master:0

Same on the other node

[root@node2 mnt]# /etc/init.d/ctdb restart
Shutting down ctdbd service:   Warning: ctdbd not running !
Starting ctdbd service:                                    [  OK  ]
[root@node2 mnt]# ctdb status
Number of nodes:2
pnn:0 192.168.1.5      OK
pnn:1 192.168.1.6      OK (THIS NODE)
Generation:1976870623
Size:2
hash:0 lmaster:0
hash:1 lmaster:1
Recovery mode:NORMAL (0)
Recovery master:0

[root@node1 ~]# ctdb ip
Public IPs on node 0
192.168.1.4 node[1] active[] available[eth0] configured[eth0]
192.168.1.7 node[0] active[eth0] available[eth0] configured[eth0]
[root@node2 mnt]# ctdb ip
Public IPs on node 1
192.168.1.4 node[1] active[eth2] available[eth2] configured[eth2]
192.168.1.7 node[0] active[] available[eth2] configured[eth2]

ctdb ping
This command tries to "ping" each of the CTDB daemons in the cluster.

[root@node1 ~]# ctdb ping -n all
response from 0 time=0.000114 sec  (8 clients)
response from 1 time=0.002473 sec  (8 clients)
[root@node2 mnt]# ctdb ping -n all
response from 0 time=0.000976 sec  (7 clients)
response from 1 time=0.000108 sec  (9 clients)

Verify your share

Creating user for accessing samba share

# useradd deepak
# smbpasswd -a deepak
New SMB password:
Retype new SMB password:
Added user deepak.

Re-try with user deepak

# smbclient -L localhost -U deepak
Enter deepak's password:[deepak's password]
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.6.9-169.el6_5]
        Sharename       Type      Comment
        ---------       ----      -------
profiles        Disk
        IPC$            IPC       IPC Service (Samba 3.6.9-169.el6_5)
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.6.9-169.el6_5]
        Server               Comment
        ---------            -------
        Workgroup            Master
        ---------            -------

The same can be verified from the windows machine.
Let me know your success and failures.