Enabling the Always-On Enterprise Making the Move to Desktop Virtualization No More Reasons to Delay By Andrew Melmed Director of Enterprise Solutions, Sanbolic Inc. April 2012 Introduction It s a well-known fact that storage plays a pivotal role in virtualization, serving as both its foundation and enabler. Yet modern storage systems and architectures continue to fall short when it comes to keeping up with the innovations in server, desktop and application virtualization technologies. As a result, many organizations (and this may be you) have found it extremely difficult to implement virtual desktops. Excessive desktop image and storage management and maintenance, performance constraints that impact the user desktop experience, inadequate fault-tolerance, and an inability to achieve enterprise scale, either hindered or completely derailed their deployments, forcing them to forego the promises of desktop virtualization (i.e., simplified desktop management and maintenance, reduced risk associated with operating system and application migrations and upgrades, and dramatic savings associated with cyclical desktop refreshes) and revert to distributing, managing and maintaining their desktop environments the old-fashioned way one desktop at a time. But as the saying goes Behind every cloud there s a silver lining. And for the hundreds of organizations around the world that found the answer to overcoming these challenges using Citrix XenDesktop in conjunction with Citrix Provisioning Services and Sanbolic Melio, the outcome has taken a dramatic turn in their favor. These companies are able to leverage the extensive capabilities and unique feature-set of the Melio software with the ease of distributing, managing and maintaining desktop images using Provisioning Services to achieve faster and greater returns on their investments in desktop virtualization. This white paper explains how organizations are using Sanbolic s innovative distributed data management software, Melio, with Citrix s industry-leading VDI solution, XenDesktop, to realize the benefits of desktop virtualization in less time, with less effort, and with lower upfront and ongoing costs than mainstream thinking perceives. About Citrix XenDesktop Citrix XenDesktop is a market-leading virtual desktop infrastructure (VDI) solution that allows organizations to simplify desktop management and maintenance, reduce risk associated with operating system and application migrations and upgrades, and save on the costs of cyclical desktop refreshes. With the recent release of XenDesktop 5.6, Citrix continues to narrow the perceived differences between virtual and local desktops from the user s experience by introducing several new features, including a new user profile manager to manage individual user settings across platforms, folder redirection to keep user data out of the virtual machine hosting the virtual desktop, and Personal vdisk technology, which brings personalization to virtual desktops by allowing users to customize their desktops (i.e., install applications, change desktop settings, etc.) without affecting the master desktop image. By offering various ways for end-users to feel as though they are working on their own desktops, Citrix is paving the way for further adoption of desktop virtualization on a much broader scale.
About Citrix Provisioning Services (PVS ) Using Provisioning Services (PVS), a core component of XenDesktop, IT administrators can deliver workloads (including OS, core applications and configuration information) to virtual machines hosting virtual desktops on-demand from a centrally-managed platform, reducing total cost of ownership while improving desktop manageability and business agility. For many organizations deploying XenDesktop, PVS affords them the ability to not only deploy virtual machines quickly and easily for VDI pilots (there s even a PVS/XenDesktop Setup Wizard that automates the task of creating virtual machines!), but also improve virtual machine performance by leveraging the caching of the contents of a desktop image file (vdisk) in the RAM of the PVS Servers during the initial streaming of vdisk image files. What s more, PVS is designed for scale. By enabling the creation and management of a large number (thousands) of virtual machines from a central console, PVS makes it easy for organizations to extend the benefits of desktop virtualization on a grand scale. To ensure business continuity, PVS includes a High Availability (HA) feature that allows virtual machines to access their vdisks through another Provisioning Server automatically when the initial server to which they were connected encounters a failure (i.e., Stream process stops, network connectivity is lost, hardware component fails, storage fails, etc.) that prevents the server from streaming the vdisks to the virtual machines. Another key benefit afforded by PVS HA is the ability to load-balance virtual machine I/O amongst all Provisioning Servers participating in a PVS Farm, providing significant improvements in performance for a richer desktop user experience. Offering high availability and load-balancing, PVS HA allows organizations to minimize system downtime and maximize user productivity. Note: To enable PVS HA for high availability of vdisks and load-balancing of virtual machine I/O, the vdisks must be accessible by at least two PVS Servers simultaneously. To achieve this, one of the following configurations must be employed: Replication: Multiple storage volumes on block-based (SAN) storage mapped to the PVS Servers (one volume per server) with a copy of each vdisk stored on each volume. This configuration is also known as the Distributed PVS HA model or Independent HA. Shared storage: A file share accessible via CIFS or a single storage volume on block-based (SAN) storage mapped to the PVS Servers, which can be accessed (read-and-write) by the servers simultaneously, with a copy of each vdisk stored on the shared volume. This configuration is also known as the Centralized PVS HA model.
About Sanbolic Melio Sanbolic Melio is an innovative, software-based product suite that augments existing application, server and storage infrastructures to avoid the challenges presented by poorly implemented and poorly managed storage architectures. By extending the benefits of virtualization to the storage layer, Sanbolic s Melio software allows organizations to realize far greater returns on their investments in applications and solutions built on platforms. Some of the key benefits attained through the use of the Melio software include: Data consolidation Infrastructure flexibility and agility Application clustering for enhanced availability and scalability Efficient storage utilization Reduced storage cost Enhanced storage performance Seamless infrastructure scale-out Simplified data and storage management Reliable data protection At the core of the Melio product suite is an advanced, 64-bit, symmetrical cluster file system called Melio FS that provides multiple servers with simultaneous read/write access to one or more storage partitions or Logical Unit Numbers (LUNs) on a storage area network (SAN). Servers SAN Storage As an all-purpose cluster file system, Melio FS supports all data and file types, enables dynamic infrastructure scale, and offers numerous options for enhancing storage performance. Offering a unified data/storage management platform, the Melio product suite includes the Melio cluster file system and Melio cluster volume manager, as well as additional tools for automating data management, providing reliable data protection and clustering applications for enhanced application availability and scalability. Advanced storage features (designed for enterprise environments) such as volume sets, stripe sets, mirror sets (RAID1), dynamic volume expansion, Quality of Service (QoS) and live storage/data migration are also included in the Melio software.
Citrix Provisioning Services and Sanbolic Melio A Winning Combination! Combining the benefits of Citrix Provisioning Services (i.e., simplified desktop image distribution, management and maintenance) with the unique capabilities of Sanbolic Melio allows organizations to deploy XenDesktop VDI pilots quickly and easily. Moreover, after completing their successful pilots, they can migrate their virtual desktop infrastructures to production just as quickly and easily (using the same servers and storage) to begin realizing an immediate return on their VDI investments. Possessing the ability to expand their infrastructures seamlessly (without system downtime) further increases their ROI on XenDesktop. How Sanbolic Melio Enhances Citrix XenDesktop With its symmetrical architecture, multi-layer locking, full journaling and dynamic cluster capabilities, Sanbolic Melio addresses the limitations and problems introduced by other storage options available for PVS HA, such as replication or file shares. Issues such as single points of failure, inefficient storage utilization, additional data and storage management overhead, and the inability to scale out a virtual desktop infrastructure without adversely affecting system performance, can make it extremely difficult for customers to deploy, manage and scale out their XenDesktop virtual desktop infrastructures in order to realize the full potential of desktop virtualization. Leveraging the inherent performance, scalability and availability characteristics of Melio and SAN storage, organizations are able to avoid the issues described above to achieve a superior return on their investments in XenDesktop. The key benefits of using Sanbolic Melio with Citrix XenDesktop include: Improved performance via dedicated, high-bandwidth connections to block-based storage. Seamless infrastructure scale-out (add more PVS Servers and/or storage dynamically). Simplified data management for desktop images (vdisks) and optionally, write cache files. Simplified storage management using a single interface to manage Melio shared volumes. High availability of vdisks, PVS and XenDesktop databases for enhanced fault-tolerance. Reliable data protection via VSS-based snapshots of Melio shared volumes. Reduced storage cost through enhanced storage utilization. The ability to transition from pilot to production at enterprise scale quickly and easily. Here s how Sanbolic Melio addresses the limitations and problems associated with the other storage options for PVS HA: Unlike file-sharing solutions such as network shares or NAS, Melio FS does not rely on CIFS (Common Internet File System) or NFS (Network File System) to provide shared access to data, allowing XenDesktop to scale by adding more PVS Servers without experiencing the locking contention issues often incurred by CIFS and NFS in larger file-sharing environments. Using Melio FS with SAN storage, storage operations are offloaded from the LAN, improving the performance and scalability of PVS and ultimately, XenDesktop. With Melio FS, when one or more Provisioning Servers lose network connectivity or encounter a system failure, the remaining servers continue to access the shared volume containing the vdisks and optionally, write cache files, thus removing any single points of failure and enhancing the fault-tolerance of XenDesktop. Unlike Disk Manager, administrators using the volume manager integrated into the Melio product suite can create and manage Melio shared volumes (basic partitions, volume sets, stripe sets or mirror sets) from a central console greatly simplifying storage management for XenDesktop.
Melio shared volumes comprised of multiple LUNs provisioned from different storage arrays can be created, allowing customers to take advantage of multiple storage controllers, additional caching and additional drives to im prove I/O performance for XenDesktop. Melio shared volumes can be expanded on the fly (without restarting disk management services or rebooting servers), allowing storage to scale quickly and easily to improve performance and/or provide additional capacity for new vdisks as the virtual desktop infrastructure grows. vdisks stored on Melio shared volumes can be protected using a simple, GUI-based utility that allows administra tors to define policies to copy or move vdisks automatically from one volume to another using VSS-based snap shots of Melio shared volumes for reliable data backup and recovery. SQL Servers can be clustered on Melio shared storage to enable high availability of the PVS and XenDesktop databases, allowing the databases to be moved to another SQL Server automatically when the initial SQL Server hosting the databases fails further enhancing XenDesktop fault-tolerance. Administrators can perform maintenance tasks (OS updates, anti-virus updates, add/remove programs, etc.) on vdisks without having to copy them from one PVS Server to another every time the contents of a vdisk are changed (as is the case with replication), greatly simplifying desktop image management and maintenance while eliminating inefficient storage utilization. The unique and extensive capabilities of Melio can also be used to create flexible, highly available shared storage from the storage within commodity (x86) server hardware. By aggregating the disks inside the PVS Servers using software-based mirroring and presenting them as a single shared storage pool that can be used to store the vdisks, this software-based storage appliance approach allows Citrix customers to take advantage of the storage already in their possession to enable PVS HA for their XenDesktop VDI pilots without incurring the expenses associated with hardware-based SAN storage (i.e., procuring, installing, configuring, operating and maintaining external storage arrays). PVS Servers This is a great way for organizations to commence VDI pilots in less time, with less effort, and with lower upfront cost. Once they ve completed their successful pilots, these companies can move to production quickly and easily using Melio s live storage/data migration feature to migrate the vdisks (while in use) onto hardware-based SAN storage, allowing them to leverage the investments in their external storage arrays and achieve the additional performance levels necessary to support the heavier I/O demands imposed by production use. At the same time, Melio will continue to simplify data and storage management and enable vdisk high availability and dynamic infrastructure scale-out to ensure the greatest return on their XenDesktop VDI solutions.
Now that we ve explained how Sanbolic Melio enhances Citrix XenDesktop, let s show you a sample illustration of a XenDesktop virtual desktop infrastructure built using Melio with SAN storage. XP Pro Vista 7 XP Pro Vista 7 XenServer /Hyper-V /vsphere Host A GigE XenServer /Hyper-V /vsphere Host B LAN SQL PVS 1 PVS 2 PVS 3 PVS 4 SQL iscsi or Fibre Channel Melio Shared Volume iscsi or Fibre Channel XP Pro vdisk Vista vdisk PVS & XD DBs 7 vdisk Conclusion Citrix-Ready certified and used by organizations around the world to enhance Citrix solutions such as XenApp and XenDesktop, Sanbolic s Melio software installs quickly and easily on all industry-standard servers (and virtual machines) running Server 2003 or Server 2008 and supports all SAN protocols, including iscsi, Fibre Channel and Infiniband. Once installed, Melio makes it easy for customers to create and manage flexible, scalable, highly-available shared storage to enable PVS HA and enhance the performance, scalability and availability of their Citrix application delivery and/or virtual desktop infrastructures. By combining the benefits of Citrix Provisioning Services and Sanbolic Melio, organizations are able to deploy XenDesktop pilots quickly and easily and with lower upfront cost. Upon successful completion of their VDI pilots, they can move their virtual desktop infrastructures into production just as quickly and easily using Melio s advanced features; and when it s time to expand their infrastructures, add more PVS Servers seamlessly to support additional virtual desktops while maintaining a rich desktop experience for their users. In all these ways, Sanbolic Melio is helping organizations realize all the benefits of desktop virtualization using Citrix XenDesktop. Sanbolic Inc. 309 Waverly Oaks, Suite 101, Waltham, MA 02452 P 617-833-4249 F 617-926-2808 E sales@sanbolic.com copyright 2012 Sanbolic Inc. All Rights Reserved.