Novell Open Enterprise Server 2 Best Practices Migration Guide - Server Consolidation & Virtualization
Server Consolidation & Virtualization
In most cases, the newer hardware being used in today's data center is considerably more powerful than that used previously. In addition, OES 2 Linux is equipped to take full advantage of these powerful servers. It is therefore reasonable to expect to consolidate the services of multiple existing NetWare platforms onto a smaller number of physical OES 2 Linux servers. This will reduce hardware, infrastructure, administrative, and licensing costs.
Novell has two tools available to perform migration and consolidation tasks.
OES Migration Tool. Novell offers the OES Migration Tool which is installed by default on OES 2 Linux servers. All operations are performed from the destination Linux server. A workstation is not required. Novell recommends using this as the primary migration tool with OES 2 Linux.
Server Consolidation and Migration Tool (SCMT). This tool is designed for consolidation procedures and is quite flexible. SCMT 1.2 is required for use with OES 2. SCMT uses a workstation to configure and initiate operations. The actual file copy is server to server.
Collectively, these tools allow for the seamless transfer of data, services, identities, printers, rights, and trustees from many NetWare servers to a smaller number of newer NetWare or Linux servers. Data and services from standalone NetWare servers can also be migrated to NetWare or Linux cluster servers.
It should be noted that each of these tools, and in some cases individual migration scenarios, have minimum prerequisite configurations that must be met for the source NetWare server. Typically, the source NetWare server must be running NetWare 6.5 SP6 or SP7. Evaluate the source servers on a case-by-case basis to determine which need to be patched in-place as part of the migration process. For example, if you have many existing NetWare servers performing similar tasks for different business units, Novell's strong recommendation is that the OES 2 Linux conversion be used as an opportunity to facilitate consolidation of similar file and print servers into a more powerful and possibly expanded cluster implementation. Special-purpose and single-purpose servers are more unique and do not readily lend themselves to consolidation. They do, however, lend themselves to XEN virtualization.
When SUSE Linux Enterprise Server 10 was released, it included the ability to run multiple self-contained virtual machines on a single physical server using XEN-based virtualization. This implementation provided out-of-the-box support for fully virtualized and paravirtualized Linux guest operating systems.
OES 2 adds the ability to run NetWare 6.5 SP7 as a paravirtualized guest operating system. You can also mix and match, hosting a SUSE Linux Enterprise server and a few NetWare servers, or vice versa on the same physical machine. In most cases, services run in a virtualized environment just as they do on a physical server and require no special configuration or other changes. You may, however, need to assign additional memory to the virtual machine depending on the load.
SUSE Linux Enterprise Server 10 , SP1 (which is included with OES 2):
- Fully supports XEN 3.0 virtualization on both 32- and 64-bit x86-based architectures
- Offers support for paravirtualization through the XEN hypervisor (full virtualization if you are running on Intel VT-x and AMD-V or using support through partners like VMware for XEN 3.0)
- Supports both Intel* VT and AMD-V chipsets (SUSE Linux Enterprise Server 10 was the first operating system of any type to support Intel VT and AMD-V).
- Offers graphical (YaST) and command-line virtual machine management tools for easy VM administration and configuration.
XEN and NetWare
With OES 2 XEN, the NetWare 6.5 SP7 operating system can run inside a virtual machine as a paravirtualized guest operating system on top of the virtual machine monitor (the XEN hypervisor). The virtual machine monitor runs between the server hardware and the SUSE Linux operating system kernel and has the responsibility for allocating resources to the virtualized guest operating systems. It presents them with virtual machines that act like the guest serversÃ¢â‚¬â„¢ native architectures.
Administrators manage NetWare in a virtual machine much the same way they manage NetWare on a physical machine. Management tools such as ConsoleOne, iManager, and Novell Remote Manager all work the same. In addition, you inherit the ability to take advantage of Linux management utilities and console commands, because the virtual machine is running in a Linux environment.
One of the major benefits of running NetWare as a virtual machine is that you can run it on existing hardware or on chipsets specifically enabled for virtualization. Even if you choose to stay on existing hardware, and if your current NetWare servers have fairly low CPU utilization, you can probably host multiple NetWare virtual machines on one of your existing servers.
If preferred, you can take advantage of the newer 64-bit processors; you are no longer 32-bit bound. You can take full advantage of the extra processing power, added memory capabilities, and improved heat and energy savings offered by 64-bit dual-core and multi-core processors.
You can also host both Linux and NetWare as virtual machines on a single box. This can facilitate migration from NetWare to Linux by allowing you to preserve access to any NetWare-dependent applications and services while you transition your IT environment and skill sets to Linux. You can also leverage a response file created during the installation of a NetWare virtual machine to create multiple NetWare virtual machines.
XEN and Other Operating Systems
XEN can also support unmodified operating systems such as Windows XP, but requires the computer running the virtualization host server to support hardware-assisted virtualization technology such as AMD* Virtualization or Intel* Virtualization Technology. Some guest operating systems hosted in full virtualization mode can be configured to run XEN-based drivers instead of operating-system-specific drivers. This improves performance dramatically in guest operating systems.
In other words, you can run XEN
- In paravirtualization mode with older CPUs and for best performance
- In full virtualization mode with Intel VT-x and AMD-V (to run Windows 2003 Server, for example)
XEN management of VMs and Guest OSs is CIM-based and supports both local and remote management consoles. Some management capabilities have been provided via YaST (start up, shut down or suspend virtual machine operating system instances and migrate VMs from one physical server to another).
Candidates for Virtualization and Consolidation
Many different types of servers can be virtualized including Linux, Windows, and NetWare. We recommend setting up a proof-of-concept XEN server to host these guests, placing many of your single purpose servers in this environment, and then rolling them to production when you are satisfied that this alternative meets your expectations.
You will need to take a close look at the current workloads of the servers you plan to consolidate. Understanding server workloads can help you prevent overloading the host with multiple servers of the same type and potentially running out of CPU, memory, or disk bandwidth.
- Disk intensive? If you load up a single physical server with multiple virtual machines that are all extremely disk-intensive, you might use up the entire bandwidth of your disk array, or you could run into contention problems if the virtual machines use the same fibre channel or iSCSI array.
- CPU intensive? Likewise, you might not want to add several servers that are CPU-intensive to the same virtual host.
The following types of servers lend themselves to virtualization:
Field Servers Ã¢â‚¬â€œ Does your network include field offices that host a significant number of services with different configuration requirements? If so, each of these different configurations could be virtualized into a single XEN OES 2 Linux physical server.
Specialized Servers Ã¢â‚¬â€œ Do you have several servers with single or specialized purposes? Most don't require a great deal of hardware resources. These servers and services could be virtualized onto a small number of powerful XEN OES 2 Linux physical servers.
General Purpose Servers Ã¢â‚¬â€œ Does your data center include numerous servers that provide the same or similar services, for example, general purpose file and print servers? This situation presents an opportunity to consolidate existing disparate file and print services into a cluster environment. If the clusters are migrated to OES 2 Linux on new hardware, a significant increase in performance and scalability could be realized.
Novell Fast Track Virtualization Engagements
If you need help determining direction for your virtualization initiative, Novell Consulting offers a two-week Virtualization Fast Track Engagement that can help you investigate options.
Fast Track engagements typically focus on two basic environments, either XEN, VMware, or both, but options for considering other vendor software can be included as needed.
Fast Track Use Scenarios
The following use scenarios, whichever one best meets your needs, can be explored:
- Application virtualization - Provision applications in a full- or paravirtualized environment. Provide application portability and flexibility across hardware platforms.
- Consolidation - Consolidate physical servers and applications into one or more virtualized environments. Leverage excess data center capacity and improve response times by balancing computing loads across data center resources at peak times.
- Business Continuity - Provide fail-over for applications and/or hardware by moving a virtual machine from one box to another with only minimal disruption to service (not noticeable to service consumers).
- Migration - Migrate applications to another machine and/or operating system or from a physical to a virtual environment. This can include migrating server workloads to virtual farms so physical resources can be redeployed for other uses.
- Deployment - Deploy virtualized operating environments.
If you are not familiar with the virtualization features of OES 2, we recommend the following resources as a starting point:
Virtualization Best Practice Guide. Recommendations for including virtualized servers in your environment are available in the "OES 2: Virtualization & Consolidation Best Practice Guide" available from the [NetWare to Linux Migration Sources] on the Novell Open Enterpirise Server Migration Web site. Novell Connection magazine. This magazine has run a series of articles over the past several months, written by Ken Baker, that introduce new OES 2 features; some of these are devoted wholly to virtualization; others contain sections explaining the advantages of virtualization and how virtualization works on OES 2. We recommend them as a quick read and an excellent source for information. See the following:
- [Sneak Peek]
- [Migrating from NetWare to OES]
- [Finalizing the Transition to Linux -The Wait Is Over]
- [Managing NetWare on a Virtualized Machine]
Novell Product Documentation. The product documentation is, of course, the primary source for information. See the following:
- Installing Hosts. For complete information about installing a virtual machine host and setting up virtual machines in general, see [Virtualization: Getting Started], particularly section 3.0, "OES 2 Linux Virtual Machines."
- Installing Quest Operating Systems. For complete information about installing NetWare 6.5 SP7 and OES 2 Linux as guest operating systems, see Section 2, "NetWare Virtual Machines" and Section 3, "OES Linux Virtual Machines," in the [Virtualization: Guest Operating System Guide].
- Running OES 2 Services on Virtual Machines. For information about installing and running OES 2 services on virtual machines, see the links in the [Virtualization] page of the OES 2 Online Documentation.