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Thanks to: http://www.serverlab.ca/ Overview In small environments, administering Linux servers using only local accounts is manageable. However, in large environments hosting many hundreds or thousands of servers, the task of administering each server, manually maintaining user accounts and passwords would be a very daunting task. A central Identity and Access solution is required to effectively manage such environments. In large Microsoft Windows datacenters, you typically see Active Directory being used as the Identity and Access solution. Samba is able to connect to your Active Directory domain to authenticate user credentials from your Windows environment. However, since Samba does not maintain a central identity store,  UID s and  GID s for each user will be different between each Samba server. Where Does This Fit In Small linux environment in a Windows-based infrastructure Before You Begin Before you move ahead with this tutorial there are a few prerequisites th

Thanks to: http://www.serverlab.ca/ Overview There are many reasons why you may want to have a local repository for your Red Hat or CentOS servers. You may be in an isolated network that has no connection to the outside world, yet you still want to keep your servers up-to-date or have all of the default packages available. Another may be that you develop and maintain your own software and need a central location to store it, where other servers can easily access it. This tutorial will show you how to configure a Yum repository server. And I promise, it is actually really simple. There are a few ways to give your other servers access to it, including HTTP, FTP, and NFS. Install Createrepo To create and intialize your Yum repository, you must first download and install the createrepo package – available from the default CentOS repos. If you do not have access to the Internet, you can install by  using the Red Hat or CentOS installation disc as a repository . Install Creater

Thanks to: http://www.serverlab.ca/ Overview It happens to the best of us. The root password for a particular server isn’t known, there are no other admin accounts available, and you need immediate access to the server.  It may have been the result of a previous employee not documenting it or maybe it was lost. Either way, it needs to be reset. Resetting the root password requires logging into single-user mode. To get into single-user mode we need to reboot the box.  You’re obviously going to experience an outage, so be sure to inform your users. The simplicity of resetting root’s password may alarm some of you. It’s important to remember that in order for you to do this, you need console access to the server. This is why your servers should be in protected area to begin with. No user should have physical access to your servers. Resetting the Password Reboot the server. During the initial boot process, you will have three seconds to press a key to interrupt it. Do so to

Thanks to: http://www.serverlab.ca/ Overview Microsoft’s Windows Server has had the ability to host NFS shares since Server 2003. There are a number of reasons why you may need it, such as backing up SharePoint or sharing files with UnixLinux computers, and for the most part it works fairly well. This tutorial will guide you through installing and configuring it. Although not covered in this tutorial, Active Directory mappings can be created for your Linux users accounts to grant them access to directories and files using NTFS shares. Hardware Configuration The sizing of your server will greatly depend on the type and volume of traffic. There absolutely is no one-size-fits-all configuration. Your success will be determined by how well you know the workload profile that the server will experience. Lots of Large File Tranfsers If your server primarly serves large files and many of them are transfered concurrently, you’re going to want a lot of RAM in the server. The RAM w

Thanks to: http://www.serverlab.ca/ Overview There was a time when teaming network interfaces was done using software supplied by the NIC’s manufacturer. And if you were administering Mircosoft servers back then, you probably remember how truly awful some of the drivers and teaming software was. With the release of Windows Server 2012, Microsoft has finally made this a native feature of the operating system. NIC teaming could not be more simple and reliable in the Microsoft server environment. Teaming Modes There are several different modes that can be used for the team. Understand the differences between each mode, as some may require advanced network hardware. STATIC TEAMING Static teaming allows you to aggregate multiple interfaces into a single connection to provide simple fault tolerance or increased bandwidth. With this mode, you can create a 40Gb team by combining four 10Gb NICs. Each connection to the team, however, is limited to the speed of the NIC it connects

Thanks to: http://www.serverlab.ca/ Overview For those on a budget or with simple needs, Microsoft’s server operating system includes a built-in network load balancer feature. Windows NLB, as it is typically called, is a fully functional layer 4 balancer, meaning it is only capable of inspecting the destination IP address of an incoming packet and forwarding it to another server using round-robin. The figure below depicts an incoming request hitting a layer 4 load balancer. The request is then forwarded to one of three web servers in the cluster. Microsoft NLB Layer 4 balancing With most load balancers, the service sits on an external appliance, as seen in the figure above. With Microsoft’s NLB, however, the web servers in the cluster are also the network load balancer. Each web server in the cluster hosts the floating IP address – known as the NLB cluster IP address. Network Infrastructure Scenario I will be using the following infrastructure to create a load balanced

This article explains how to configure your Windows Server 2008 R2 Active Directory Primary Domain Controller to syncronise time with an external time source. Note: In an active directory, all member computers will sync time with the PDC, so you only need to setup an external time source on the PDC. Open an  elevated command prompt  and type the following: Net Stop W32Time W32tm /config /syncfromflags:manual /manualpeerlist:"0.pool.ntp.org, 1.pool.ntp.org, 2.pool.ntp.org, 3.pool.ntp.org" W32tm /config /reliable:yes Net Start W32Time W32tm /config /update W32tm /resync You can run  W32tm /resync  on member computers to sync time with the PDC.  The windows time service should begin synchronizing the time. You can check the external NTP servers in the time configuration by typing:  C:\>w32tm /query /configuration Check the Event Viewer for any errors. Other Information:  http://adriank.org/windows-server-2008-r2-sp1-sync-time-external-time-source/ Exter