Virtualization's new voice: virtualization plays an important role in an overall data management strategy.Virtualization An umbrella term for enhancing a computer's ability to do work. Following are the ways virtualization is used.
Partitioning the computer's memory into separate and isolated "virtual machines" simulates multiple machines within one physical computer. seems to have made a comeback of sorts lately. Only four short years ago, "storage virtualization Treating storage as a single logical entity without regard to the hierarchy of physical media that may be involved or that may change. It enables the applications to read from and write to a single pool of storage rather then individual disks, tapes and optical devices. " was viewed as the ultimate solution for managing storage. But as a core technology in and of itself, the buzz quickly evaporated evaporated
reduced in volume by evaporation; concentrated to a denser form. . The downfall of virtualization seemed just as fast as its ascent in the storage industry.
But listen carefully as whispers of virtualization are getting louder. The current reality is that when spoken in conjunction with enabling storage services such as replication, mirroring and rapid data recovery, virtualization has a new voice and serves as a key enabling factor for the proliferation proliferation /pro·lif·er·a·tion/ (pro-lif?er-a´shun) the reproduction or multiplication of similar forms, especially of cells.prolif´erativeprolif´erous
n. of data services in an environment with a heterogeneous operating system operating system (OS)
Software that controls the operation of a computer, directs the input and output of data, keeps track of files, and controls the processing of computer programs. and multiple storage devices. Virtualization can play a vital role in overall data management strategy. This article will examine the factors behind the renewed attention being paid to the virtualization story and why that attention is justified when used in conjunction with storage services.
Virtualization is not all it's cracked up to be, without the proper framework. Clever "virtualization" technology masks the differences in storage hardware and presents a unified way to interact with disk/tape devices from different manufacturers.
The true value of virtualization can only be realized within a full-featured storage solution that leverages a customer's current IT infrastructure and provides not just virtualization but top performance (fast data storage and access), ease of use, unified SAN and NAS (1) See network access server.
(2) (Network Attached Storage) A specialized file server that connects to the network. A NAS device contains a slimmed-down operating system and a file system and processes only I/O requests by supporting the popular management, virtualization across cabinets (not just within one storage cabinet), and seamless support of heterogeneous storage environments. For a virtualization solution to make business sense, it must offer total freedom of choice in device vendors, interfaces, connectivity, platforms and protocols.
But where does it make sense to virtualize To cause a virtual technique to be performed. See virtualization. ? Disk-level virtualization is limited to specific vendor devices and, at the application host-level, it can be seen as a synonym synonym (sĭn`ənĭm) [Gr.,=having the same name], word having a meaning that is the same as or very similar to the meaning of another word of the same language. Some are alike in some meanings only, as live and dwell. for volume management--host-based, operating system-specific, and with a point of control on every single machine on the network. Ideally, storage virtualization has no operating system specificity and can be managed centrally, rather than from each host in the environment. A true virtualization model cuts across vendor barriers.
The most effective location for virtualization is in the storage network. By interjecting a layer of intelligence between servers and storage, network-based virtualization offers the most freedom from operating system constraints and vendor-specific storage devices. It is also completely centralized cen·tral·ize
v. cen·tral·ized, cen·tral·iz·ing, cen·tral·iz·es
1. To draw into or toward a center; consolidate.
2. , as the intelligent "nodes" can be managed from a single point of view.
A well-architected "network-based" storage infrastructure software should be able to virtualize the disk and/or tape storage from multiple vendors, provision the virtual disk to the host-attached Fibre Channel/iSCSI/CIFS/ NFS (Network File System) The file sharing protocol in a Unix network. This de facto Unix standard, which is widely known as a "distributed file system," was developed by Sun. See file sharing protocol and WebNFS.
NFS - Network File System network while provisioning the virtual tape to hosts attached to the Fibre Channel and iSCSI networks, and associate mission-critical storage services (replication, snapshot, backup, HSM (1) (Hierarchical Storage Management) The automatic movement of files from hard disk to slower, less-expensive storage media. The typical hierarchy is from magnetic disk to optical disc to tape. , etc.) to the logical disk and/or tape. It should be so seamless that an ISV (Independent Software Vendor) A person or company that develops software. It implies an organization that specializes in software only and is not part of a computer systems or hardware manufacturer. developing an application in Windows does not have to worry about the underlying storage devices or protocols.
As another example: With virtualization, good RAID software should present a logical disk (RAID-0 or 1 or 5, etc.) to the upper layer, and allow the user to employ the SCSI/Fibre Channel/ATA/SATA disk from any manufacturer; smart RAID software should enable the application/administrator to expand or shrink the logical disk on-the-fly, and be able to perform snapshot, replication, backup, etc., in real time without affecting the upper layer application; and a network-based, intelligent RAID software should be able to offer "logical disk" but also "logical tape" and allow the application host to access the logical disk through the Fibre Channel/ iSCSI/CIFS/NFS network and the logical tape through the Fibre Channel/iSCSI network.
Significant Benefits in Data Management
Built on a solid foundation, virtualization offers significant benefits in data management. Implemented effectively, virtualization offers a layer of abstraction See abstraction layer. above the physical layer of disks and spindles. The issue with the physical layer is that it varies from vendor to vendor, and even between device models from the same vendor, making storage provisioning quite a challenge. A virtualization solution unifies everything (RAID and JBOD (Just a Bunch Of Disks) A group of hard disks in a computer that are not set up as any type of RAID configuration. They are just a bunch of disks.
JBOD - Just a Bunch Of Disks , iSCSI, SCSI SCSI
in full Small Computer System Interface
Once common standard for connecting peripheral devices (disks, modems, printers, etc.) to small and medium-sized computers. SCSI has given way to faster standards, such as Firewire and USB. and Fibre Channel) and makes it all look the same. In short, it provides a utility model for storage. Disk space is carved out of a pool and assigned to servers without any need to physically touch the servers.
What storage virtualization brings to the table is a way of incorporating storage services into the network, without any reliance on operating system or storage-specific tools. This is the true business benefit, and what many end users are beginning to realize.
As an enabler of services addressing the storage pain of IT administrators, virtualization now speaks a language IT administrators can understand.
Supports Remote Data Access, Backup, Mirroring, Replication
A value-added storage virtualization solution enables IT administrators to create backups and mirror space on disks configured virtually anywhere in a system or across IP networks. It enables disaster recovery services such as replication of data across IP to a remote site, and rapid data and system recovery services such as bare metal 1. bare metal - New computer hardware, unadorned with such snares and delusions as an operating system, an HLL, or even assembler. Commonly used in the phrase "programming on the bare metal", which refers to the arduous work of bit bashing needed to create these basic tools recovery and online/nearline disk-based backups. This not only eases administration for the local SAN managers--since they can remain at their central location--but also benefits the entire enterprise, since it makes critical data inexpensively available outside a geographically local area. And, of course, it ensures that a business can continue operating in the event of damage or loss of a primary data set.
Ensures Business Continuity
Virtualization allows for rapid storage growth and reconfiguration, without the downtime The time during which a computer is not functioning due to hardware, operating system or application program failure. that expansion usually entails. This is a vital advantage for today's enterprises, which are increasingly running in fast-paced 24x7 mode. Volumes of storage can be allocated to application servers on the fly, without interrupting operation.
In order to truly assure business continuity, an advanced virtualization solution should make it possible to safeguard against all possible single points of failure on storage devices, server hardware, networking hardware Networking hardware typically refers to equipment facilitating the use of a computer network. Typically, this includes routers, switches, access points, network interface cards and other related hardware. , and even complete site failure due to disaster. In an age when businesses can't operate without access to their data, less downtime and disaster protection translate into higher returns for enterprises.
To guard against failure of storage systems, the solution should enable mirroring of virtual disks, and not just within cabinets but also across cabinets--even if they are made by different vendors--and across any distance. To defend against server hardware failure, an advanced virtualization solution should support high availability Also called "RAS" (reliability, availability, serviceability) or "fault resilient," it refers to a multiprocessing system that can quickly recover from a failure. There may be a minute or two of downtime while one system switches over to another, but processing will continue. configurations, enabling full redundancy throughout the entire data path so that there is no single point of failure. To protect against site failure from a variety of disasters, the solution should support remote replication of virtual disks to keep an extra set of data off site.
Facilitates Fast Data Access
For all intents and purposes Adv. 1. for all intents and purposes - in every practical sense; "to all intents and purposes the case is closed"; "the rest are for all practical purposes useless"
for all practical purposes, to all intents and purposes , a virtualized volume mimics an actual physical device. However, a superior virtualization solution succeeds at generating virtual disks that far surpass their physical cousins in speed and functionality. In this way, virtualization can significantly improve the performance of a storage network. This is crucial, as speedy access to data is a critical benchmark for modern enterprises whose customers want products fast and demand answers now.
Virtualization, in combination with other functionalities, can be particularly beneficial when performing tape backups Using magnetic tape for storing duplicate copies of hard disk files. Users can add an internal or external tape drive to their desktop computers for backup purposes, and files are typically copied to the tapes using a backup utility that updates on a periodic schedule. . Virtual volumes can be staged on disks and later backed up to tapes, thus offloading I/O (Input/Output) The transfer of data between the CPU and a peripheral device. Every transfer is an output from one device and an input to another. See PC input/output.
I/O - Input/Output and processing cycles from the application server. For example, by leveraging IPStor software's delta-based snapshot techniques and/or virtual tape technology, truly LAN-free/server-less/windowless backups become a reality.
Enables Interoperability With Storage Hardware
Another key benefit of virtualization is interoperability. Masking the complexity of various vendors' storage solutions ideally creates an environment where every disk subsystem appears the same to the host server. The actual disk subsystem behind the virtual image can be anything. In a virtualized storage architecture, enterprises can purchase their storage knowing that it can just be plugged in to start working, without complex and time consuming configurations--or a total lack of interoperability--thus significantly decreasing their investment and increasing financial return.
Virtualization can keep enterprises immune to becoming captive to a specific vendor or proprietary technology and the higher initial and recurring costs that this tends to involve. Because virtualized storage is agnostic with respect to vendors and technology, IT administrators are given the freedom to choose the best solution for their organization. This also encourages healthy competition in the storage appliance industry, bringing added benefits over time in the form of technological advances and fine-tunings.
Reduces Managerial and Administrative Overhead
A storage infrastructure that employs virtualization is considerably easier for IT administrators to manage, saving them a great deal of time and effort. Instead of expending huge chunks of time on hardware modifications--physically attaching, moving around and configuring devices--they can effortlessly assign, unassign, or reassign virtual volumes from a central location. Not only does this leave administrators with more time to do all of the other things on their plates, it saves enterprises resources, as fewer IT staff are needed to manage much larger amounts of storage.
Easy, Effective Management of Storage Network/Devices
A virtualized approach makes it much easier to add and maintain storage devices. An advanced solution applies an intuitive Graphical User Interface graphical user interface (GUI)
Computer display format that allows the user to select commands, call up files, start programs, and do other routine tasks by using a mouse to point to pictorial symbols (icons) or lists of menu choices on the screen as opposed to having to (GUI (Graphical User Interface) A graphics-based user interface that incorporates movable windows, icons and a mouse. The ability to resize application windows and change style and size of fonts are the significant advantages of a GUI vs. a character-based interface. ) to visualize storage and then assign and manipulate it as needed as needed prn. See prn order. . Furthermore, dynamic modification of access permissions to virtual volumes can be performed on the fly. Online and transparent migration of storage devices allows maintenance and upgrade of storage devices without shutting down applications.
While, in the past, virtualization was more heat than substance, things are settling down now. The argument for storage virtualization is now becoming too compelling for IT administrators to ignore, as they are now hearing the value proposition of open storage services platforms.
Gabriel Lopez is product manager at FalconStor Software, Inc. (Melville. NY)