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n°18  |  September   2007
Experts voice

Virtualization offers much more than just back-up cost reduction
Interview with Philippe Schreck,
Product Marketing Director for the Storage Business Unit

Philippe has devoted much of his professional life to data storage: having started his career in charge of Bull developments of storage products, he went on to be technical director of the Bull 2AI subsidiary dedicated to storage, and is today Product Marketing Director for the storage Business Unit.


Huge increases in the volumes of data being handled as a result of putting business processes on line, globalization of exchanges, new regulations requiring backup and recovery times that are increasingly hard to achieve within the allotted time windows... At the same time, infrastructures are becoming more and more complex, and heterogeneity is becoming the norm.
The main issues faced today by CIOs and their staff include: guaranteeing access to back-up data whatever technologies have been used, and even in the longer term; meeting the challenges posed by heterogeneous infrastructures; improving the performance of backup/recovery operations; optimizing available resources; reducing costs; and automating to secure procedures.
To respond to these problems, many customers are turning to VTL (Virtual Tape Library) type solutions. Since 1997 Bull has been marketing and constantly enriching its archive virtualization solution, StoreWay Virtuo.

What is a VTL?
The VTL, or Virtual Tape Library is a storage solution designed to emulate magnetic tape on a disc space. A VTL is integrated within a Storage Area Network (SAN) or IP storage network, and interfaces with the back-up server that configures the robotic resources, media and tape drives making up the magnetic tape library.
During the back-up operation, the VTL saves the data to a disc cache. The increase in the number of virtual drives simply enables the degree of parallelism to be increased. The data will be migrated later to magnetic tape, without transit and therefore without affecting either the application servers or the back-up servers, and so allowing the whole of the available time window to be utilized, while minimizing the number of real drives required. These data are then conserved in the disc cache once they have been written to tape, and this means data can be restored subsequently within a specified time, independently of their position on the tape, allowing Recovery Time Objective to be met.
VTL is designed, then, to compensate for the disadvantages of tape storage, the most important of these being the inevitably low recovery performance, via an intermediate disc system sandwich layer within the configuration.

Why continue to use magnetic tape when discs are faster, especially where data recovery is concerned?
Magnetic tape is an eminently affordable medium, and has been the most commonly used system for data archiving in the past. These systems are therefore often found, particularly in larger organizations that have IT installations dating from many years ago.
Nevertheless, since the beginning of the first decade this century and the arrival of the SATA format, hard discs have been steadily dropping in price, and at the same time offering ever larger disc storage capacity. So this technology has been increasingly competing with magnetic tape in a market segment that until now has been quite protected.
Hence the idea of combining the two technologies to gain the advantages offered by both. VTL systems constitute a way of optimizing back-up and recovery performance. Magnetic tape will still be the medium of choice for long-term data storage, but VTLs are becoming indispensable to guarantee the daily service quality.

Advantages of the Bull StoreWay Virtuo solution
StoreWay Virtuo is our back-up consolidation solution. Over and above the basic VTL functionalities, we have developed advanced functionalities that better fulfill the back-up needs of IT centers more effectively, whatever operating systems they use.
The emulation of several magnetic tape libraries for the purpose of supporting simultaneous connection to several back-up servers, whether these are of the same type or not, enables heterogeneous back-up environments to be consolidated on a single storage space.
Configurable rules for transferring data from disc to tape enable intelligent management of storage resources, while remote copying functions enable deployment of automated continuous activity plans.
StoreWay Virtuo provides the means for data to be securely shared, and offers extremely high levels of performance, flexibility, and availability both for open and mainframe systems.

The most significant benefits to customers
The main advantages offered by StoreWay Virtuo are reduced costs, simplified archive management and more effective management of complexity.

High levels of performance
Using disc-based data caches enables rapid back-up and recovery, and as a consequence, shorter timeslot allocation. The cache storage lifespan is configurable, and this simplifies the management and administration of the data lifecycle while enabling archiving requirements to be tailored to suit current operational constraints.

Open architecture
Incorporating StoreWay Virtuo into existing environments is transparent, and customers can use their existing back-up strategy, whatever form this takes, once they have upgraded their protection system to StoreWay Virtuo.
StoreWay Virtuo operates both in open environments (Unix, Linux and Windows, NAS/NDMP) and on mainframes (Bull GCOS, and IBM MVS/zOS). It also supports the majority of back-up applications (Symantec NetBackup, EMC2 NetWorker, IBM TSM, etc.) and standard libraries (Sun/StorageTek, Overland and Quantum/Adic, etc.), whatever the drive technology being utilized (LTO, SDLT, 9x40…).

Business continuity planning
To respond to the needs of nearly 70% of customers, StoreWay Virtuo features a ‘vaulting’ mechanism: this is the capacity to use a second library to create a copy of a second back-up event directly in a remote site. This option relieves systems administrators of the day-to-day tasks relating to the physical handling of magnetic tape cartridges, and particularly transfers made externally between different sites. In addition, StoreWay Virtuo can operate in failover mode on different sites, enabling guaranteed service continuity in the event that one of the two sites is no longer accessible.

Cost reduction

  • Consolidation and optimization of archiving resources. StoreWay Virtuo gives the systems administrator transparent access to the full complement of back-up silos from a single point, even in heterogeneous environments mixing open and mainframe systems. This not only saves time but also saves money as there is no need for an application dedicated to this aspect of storage.
  • Easy administration. Centralized administration, and one that is easy to use, facilitates all tasks related to data protection conformity.
  • Transparent utilization of new drive technologies in back-up environments. StoreWay Virtuo supports various drive and tape technologies so customers can adopt new magnetic tape storage technologies without having to alter their existing environment. It also enables older environments to use new drive technologies which would not have been supported by the suppliers of these former environments.
  • Up to 80% reduction in the number of cartridges used StoreWay Virtuo optimizes the filling up of physical cartridges, using the following techniques:
    - Stacking: the writing of several logical volumes on a single physical tape
    - Compacting: the recopying of valid back-ups stored on different physical tapes onto a new physical tape, so these physical tapes are re-useable.
    These technical advantages enable substantial savings to be made in terms of physical cartridge consumption.
  • Up to 90% reduction in the number of drives used thanks to the optimized utilization of the physical drives present.

Two significant operational examples
We have one French customer, for example, who wanted a back-up solution that would let them consolidate their entire storage environment between IBM mainframes and open systems, improve back-up and recovery time-windows while taking on board increased data volumes, conserve their existing tape handling systems, and continue using their usual procedures. In addition, they wanted a performance warranty for the back-up virtualization solution until 2010 and the certainty of service continuity.
The Bull StoreWay solution has not only met these requirements, but has also enabled significant economies in operating costs to be made. Typically, the StoreWay Virtuo solution takes up 10 times less floor space than previously, and uses 20 times fewer cartridges!

The pictures below illustrate this example

Before Virtuo :
library footprint

After Virtuo :
footprint for the entire solution

Another customer based in the United States was highly impressed by the cost savings StoreWay Virtuo had brought about, reflected in economies not just in floor space and consumables, but also in systems administration (the system required just one operator working one eight-hour shift a day, to replace two operators working three eight-hour shifts).

To conclude
Bull is a pioneer in designing and developing VTL technology for heterogeneous IT environments. Its StoreWay Virtuo solution is particularly designed to:
1. Consolidate heterogeneous, mainframe and open environments
2. Guarantee the kind of transparent back-up needed to support Disaster Recovery operations
3. Optimize resources, providing up to 90% reduction in back-up and recovery resources.
Bull continues to enhance the StoreWay Virtuo solution for the benefit of customers, and to adapt it to suit their constantly evolving environments.

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