Two ways to manage different server operating systems

Running multiple server operating systems in a data center allows users to work with whichever systems they choose, but it also creates management issues.

Setting up and maintaining different systems can be complex and time-consuming. System administrators have access to a plethora of vendor and third-party tools that reduce the load.

The first step in supporting a heterogeneous data center is to configure the server to support multiple operating systems. Administrators can either rely on hardware sequestration or hide lower-level idiosyncrasies with a layer of virtualization.

Give them the boot(s)

Multi-booting is a common technique for companies running multiple server operating systems. The system administrator independently installs different environments on multiple physical disks or logical disk partitions. Next, the system administrator selects the preferred operating system from a menu that appears when he boots the system.

To set up a multi-boot system, create a separate area on disk for each environment. This usually involves dividing a single hard drive into multiple partitions. Each server’s hard disk has a Master Boot Record (MBR) that contains a partition table, which specifies how to separate the disk into logically distinct areas.

When the system boots, the basic input/output system searches for an appropriate boot device, reads the MBR from the disk, and executes a small amount of code. The boot code examines the partition table to determine which one is active, then loads the information – the volume’s boot sector – at the start of that partition and executes it, transferring control to the operating system’s loader.

Windows has built-in capabilities to manage disk partitions.

Third-party products, such as EaseUs Partition Master, MiniTool’s Partition Wizard, and Aomei Technology’s Partition Wizard automate the process. Typically, these products delete any existing Windows partition and then create new partitions in the sizes you specified.

The second operating system will probably be a version of Linux. Two boot loaders, LInux LOader and Grand Unified Boot loader, perform a function similar to MBR.

If a company is running Unix, vendors such as HP, IBM, and Oracle include partitioning features in their system administration product lines. Parted Magic LLC offers an eponymous tool, Tenorshare Render Partition Manager, and there are others.

Once you have configured multiple partitions on the hard drive, determine where to store company data. Often, administrators want to centralize data rather than tying it to an operating system. To do this, configure an additional logical partition for data.

Partitioning has drawbacks. The more partitions created, the more items to manage. Determining how much space to partition can be a challenge as applications fluctuate in their system requirements. It takes time to add space to partitions after they are created.

Host in a VM

A different approach to hosting multiple environments on a server is to run them in virtual machines. Virtual machines allow computers to emulate a complete hardware environment in its software. While running an operating system, the administrator can launch a virtual machine as if it were another application.

Virtual machines run multiple operating systems side-by-side and simultaneously. Since each virtual machine has its own IP address and its own virtualized network connection, a small network of computers appears within a server. Administrators can perform the same tasks on guest servers as with a host, such as running programs, sharing files, and partitioning disk space.

Disadvantages include reduced speed – a consequence of hardware emulation with software – and the added cost of VM software – usually from Microsoft or VMware.

Server updates

Once a company has configured servers, updates are made regularly. Microsoft provides Windows Server Update Services (WSUS), which is automatically installed on Windows servers. Security updates can be distributed and managed through the administration console. Server admins can also get updates from Microsoft Windows Update, with automatic update downloads from Microsoft. You can also turn it off and periodically check for updates.

Unix systems include similar functionality. For example, Oracle Enterprise Manager Ops Center reduces the complexity of updating large numbers of systems, standardizes the update installation process, minimizes downtime, and allows an administrator to choose the level automation.

Upgrading Linux can be difficult, especially if the data center uses multiple Linux distributions. Although the operating system is designed to be consistent across distributions, nuances do exist. Therefore, the user is often tied to the distribution provider’s update tools.

About the Author:
Paul Korzeniowski is a freelance writer specializing in data center issues. He has been writing about technology for two decades, is based in Sudbury, MA and can be reached at [email protected].

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