HOW TO RESTORE OFF A MOUNTED SLAVE DISK ON REDHAT + CPANEL (CRASH/HACK/BAD KERNEL)

How to Restore off a mounted slave disk on Redhat + Cpanel (crash/hack/bad kernel)

Warning: This is not to be done by the unexperienced admins bad things could happen. Hire someone.

Sometimes if you get hacked or boot with a bad kernel you need to have the datacenter mount your old drive, and install a new one with a fresh installation of redhat. First things first lets make sure you have an updated kernel, we will do it with up2date for ease of use:

up2date -f kernel

check the grub.conf /or lilo config to ensure the settings are right. (if using lilo run this command aswell /sbin/lilo -v -v and check for errors)

Now reboot the server

shutdown -r now
I. Mount the backup Drive

First check to see if there are any drives mounted.

df -h

You should get something simular to this if it isent mounted yet:

[root@localhost root]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda2 37G 1.4G 33G 4% /
/dev/hda1 101M 7.7M 88M 9% /boot
none 125M 0 125M 0% /dev/shm
[root@localhost root]#

if it is mounted you will see something like this:

-bash-2.05b# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda3 53G 31G 20G 62% /
/dev/hda1 99M 14M 80M 15% /boot
none 248M 0 248M 0% /dev/shm
/dev/hdc3 53G 31G 20G 61% /mnt/old
-bash-2.05b#

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first login as root to the server. please note this should have "yum" install already. my recommendation is to use standalone server or virtual server for monitoring . its depend on your network size.

# yum install mysql-server mysql php-mysql php-pear php-common php-gd php-devel php php-mbstring php-cli php-snmp php-pear-Net-SMTP php-mysql httpd

Configure MySQL server

# mysqladmin -u root password NEWPASSWORD

Create cacti MySQL database

In enterprise level network its common to have HQ(Head Quarters)-Branch Office network. These branch offices may required to connected with HQ resources for its operations. Most of the time this kind of setup uses WAN links to connect branch Offices with HQ network. Let's assume we have company called ABC and its HQ is located in Canada Toronto. Due to the Expansion its need branch office open in London, UK. So the requirement is more complicated as its 2 different countries.

The users in London office still need to authenticate the company domain environment and access the resources. Let's Look in
to some of the difficulties, challenges faces with typical this kind of setup.

Lack of Resources

To connect HQ with branch site its required secure, reliable connection. But these connections typically comes with high $$$$ cost. Even though its cost mostly these links will be with speed of 128kb, 256kb, 512kb etc. If users in branch site is authenticating company AD it will use WAN link for the all the authentication, resources access etc. if the number of users increase in branch site the link utilization just for the AD activities will increased. Also since its between different geographical locations, different ISP, many facts will affect the reliability of the link as well. what happen if the WAN link went down on critical business day ? so solution is to deploy AD in branch site and it will be opening whole different range of concerns, problems.

In RODC environment one of the great feature is the password replication. in RODC environment we can determine which passwords need to be cache in RODC and which accounts still need to be authenticate via writable domain controller. As example domain administrator accounts do not need to be cached on RODC. its always safe if it can be authaticate via routable DC for security purposes. so if a domain administrator login from a RODC enviornment, we can set system to forward the authtication request or service ticket to the writable domain controller.

Microsoft made this easy by introducing password replication policy (PRP) to RODC environment. by default system create domain-wide password replication policy two domain local security groups.

Allowed RODC Password Replication Group : Members of this group will allow to cache passwords in RODC. by default this group do not have any members.

Denied RODC Password Replication Group: Members of this group are deny to cache passwords in RODC. Some of the groups which are security critical are member of this group by default such as Administrators, Server Operators, Backup Operators, Account Operators.

One of the biggest mistakes administrator do is only allow/deny user accounts. But computers it self also uses authatication and service tickets requests. so make sure you add computer accounts also in to these lists.

How to configure RODC password replication policy(PRP) ?

1) Login to a writable domain controller with domain administrator account
2) Open "Active Directory Users and Computers" snap in by Server Manager > Tools > Active Directory Users and Computers
3) Go to "Domain Controllers" OU

4) Click to select the RODC you need to configure PRP. Then right click and click on properties.

5) In the properties window click on "Password Replication Policy" tab

Before install a RODC in a domain environment it need to meet the following requirements,

Forest function level should be windows 2003 server or higher
Needs at least one writable domain controller running windows server 2008 or higher

If forest have any DC running windows server 2003 we need to adjust permissions on DNS application directory partition to allow them to replicate to RODC. It can be done by running adprep /RODCprep from windows 2012 server installation disk \support\adprep folder.

In my demo setup i do have a domain called contoso. Before start lets check the forest function level.

To do that, log in to the DC as domain admin and open "Server Manager"
Then from tools click on "Active Directory Domains and Trust"

Right click on domain and select "Properties"

As we can see here its runs with windows server 2012 R2 so we do not need to prepare domain

This is the part 3 of the series of articles which explains complete setup of VPN in windows serverenvironment.

Configure Logs

To maintain the security and the monitor the issues involve with the remote access it’s important to configure proper logs. NPS keeps separate logs for this process. In below I will demonstrate how to configure these logs.

1. Open the network policy server mmc.
2. In the console click accounting.

3. In the detail panel click configure local file logging. Then local file logging box will open.

4. On the log file tab, it is possible to define the directory the log files should store. Also by selecting “database-compatibility” the files will be save on IAS format which allow to open it from database level.

Even its been over decade after windows server 2003 release , It’s no wonder that still organizations using windows server 2003 / windows server 2003 R2 as their domain controllers. Microsoft has announced that windows server 2003 / windows server 2003 R2 supports ends on 2015, July 14th (http://support2.microsoft.com/lifecycle/search/default.aspx?sort=PN&alpha=Microsoft+Windows+Server+2003&Filter=FilterNO). So the day has come to plan out for the upgrades if you still running those versions in infrastructure.

This guide will explain how we can transfer DC FSMO roles from windows server 2003 to windows server 2012 R2 which is latest. In Windows DC environment FSMO roles holds all the information about DC and its necessary to have all this 5 roles working correctly to maintain proper DC environment. The 5 FSMO roles as following,

•    Schema master
•    Domain naming master
•    RID master
•    PDC emulator
•    Infrastructure master

You can find more information about this roles from http://support.microsoft.com/kb/197132

For the demonstration I am using the following setup

Server Name	Operating System	Server Roles
canitpro-dc2k3.canitpro.local	Windows server 2003 SP2 x86	Active Directory FSMO roles, DNS
CANITPRO-DC2K12.canitpro.local	Windows server 2012 R2 x64	Additional Domain Controller, DNS

So in here I already added windows 2012 r2 server to domain and make it additional domain controller. Currently it do not hold any FSMO roles. My plan is to migrate all the FSMO roles in to windows 2012 r2 server.

Note : In before if we adding windows 2008 server to windows 2003 environment, first we need to prepare the forest and domain schema by running adprep \forestprep and adprep \domainprep from windows 2008 source files \ support \ adprep. But in windows 2012 you do not need to worry about it when adding 2012 as additional domain controller. When you run the dcpromo it will automatically update it in windows 2003 remotely.

Microsoft has already announced that windows server 2003 / windows server 2003 R2 versions support is coming to end in 14th July 2015 (http://support2.microsoft.com/lifecycle/search/default.aspx?sort=PN&alpha=Microsoft+Windows+Server+2003&Filter=FilterNO). It’s no wonder that some organizations still uses windows server 2003 versions in production environment.

If you still not plan for migration from legacy windows server versions, well time has come!!

This guide will explain how we can migrate AD CS from windows server 2003 to windows server 2012 R2.

In this demonstration I am using following setup.

Server Name	Operating System	Server Roles
canitpro-casrv.canitpro.local	Windows Server 2003 R2 Enterprise x86	AD CS ( Enterprise Certificate Authority )
CANITPRO-DC2K12.canitpro.local	Windows Server 2012 R2 x64	-

Backup windows server 2003 certificate authority database and its configuration

• Log in to Windows 2003 Server as member of local administrator group
• Go to Start > Administrative Tools > Certificate Authority

• Right Click on Server Node > All Tasks > Backup CA

• Then it will open the “Certification Authority Backup Wizard” and click “Next” to continue

• In next window click on check boxes to select options as highlighted and click on “Brows” to provide the backup file path location where it will save the backup file. Then click on “Next” to continue

Microsoft has already announced that windows server 2003 / windows server 2003 R2 versions support is coming to end in 14th July 2015

It’s no wonder that still organizations using windows server 2003 / windows server 2003 R2 in their infrastructure with different server roles.

With windows server 2008 R2 Microsoft has introduce new great feature called “Windows Server Migration Tools” which will allow administrators to migrate server roles, features, configuration settings seamlessly from one system to another(ex- windows server 2003). Windows server 2012 also includes this feature and in this article I will demonstrate how we can use it to migrate DHCProle to windows server 2012 r2.

Please note, To use this method we need to install this feature in both source and destination servers.

For the demonstration I am using following setup

Server Name	Operating System	Server Roles	Networks
dhcp-2k3.canitpro.local	Windows Server 2003 R2 Enterprise x86	DHCP	Network A – 10.10.10.0 Network B – 172.16.25.0 Network C – 192.168.148.0
CANITPRO-DC2K12.canitpro.local	Windows Server 2012 R2 x64	-	-

Before start the migration process it’s important to consider on following.

1)    To migrate the roles you need to log in to source and destination servers as “Domain Administrators”.
2)    Before start the migration process make sure source and destination servers’ runs with latest updates and service packs.
3)    If the source server runs with multiple network, multiple NIC make sure the destination server also have same number of NIC so it can be server with same network setup.

dhcp-2k3.canitpro.local server currently setup with 3 additional NIC to represent network A,B and C. those have configured with static ip addresses to match with relevant network it belongs to. The DHCP server host different DHCP scopes for each network.
Before we start the process we need to install the following software in windows server 2003(dhcp-2k3.canitpro.local) if it’s not there already.

1) .Net Framework 3.5 (http://www.microsoft.com/en-us/download/details.aspx?id=21)
2) Windows PowerShell 2.0 (http://support2.microsoft.com/kb/968929/en-us)

Install Windows Server Migration Tools in windows server 2012

1) Log in to the Windows server 2012 as Domain Administrator
2) Go to Server Manager > Add Roles and Features

3) It will open the Add roles and features Wizard and click next to start the process
4) In next window, for the installation type select “Role-based or feature-based installation” then click next to continue