Moving Beyond Tape Recovery

Transcription

1 Moving Beyond Tape Recovery It is time to reexamine tape-based backup and recovery strategies to take into account today's dynamic and demanding business environment and newer, more advanced backup and recovery solutions.

2 Executive Summary Ever since computers first found their way into businesses, magnetic tape has been the workhorse of the data backup and recovery strategies that businesses use to protect their critical information resources. Is it finally time to give the workhorse more horsepower? Tape offers the lowest cost-per-megabyte among existing enterprise storage options, but dramatic reductions in disk costs have narrowed the gap between tape and magnetic disk significantly.this disparity continues to diminish rapidly and is already small enough for many companies to justify switching to disk for data backups. It is inexpensive to ship a tape to an offsite vault; out of harm's way should a disaster strike the primary data center. In the past this has given tape an advantage, but reductions in telecommunication costs now make it economical to transmit large volumes of data quickly from a disk in one data center to another in a remote location. Cost and portability are the only advantages, diminishing though they are, that tape still wields over disk. In contrast, the use of disk as a backup medium boasts significant rewards. Foremost is recovery speed. A remote replica server kept up-to-date continuously over high-speed telecommunication lines can take over almost immediately should a disaster knock out the primary data center, compared to the many hours or even days needed to recover from tape. Disk-based solutions can also minimize the amount of data lost in the event of a disaster by synchronizing a remote backup server with the primary server in real-time. In contrast, a backup tape may contain data that is more than a day out of date. Tape-based backups also tend to disrupt business operations because the organization may need to stop or curtail applications to create the backup tape. To overcome the drawbacks of tape, companies can deploy fully redundant systems, maintained by sophisticated data replication software, with automated recovery processes. However, these options may require a larger investment than some companies can justify.these companies need a solution that delivers the reliability and speed of disk backups, without the high cost of a fully redundant system. Fortunately, a breakthrough disk-based recovery solution, MIMIX dr1 from Lakeview Technology, does just that. 2

3 Reasons to Review Your Disaster Recovery Strategies For years now, most companies backed up their data to tape nightly or weekly to provide a mechanism to recover their data should disaster strike. Since this has been standard practice for some time, you might well ask, "Why should our company's Disaster Recovery capabilities move back up to the top of my agenda?" There are three reasons. First, disasters happen. They are rare, but they do occur. In the context of this report, a disaster is anything that results in a serious loss of vital data. This includes natural disasters, such as fires, floods and earthquakes; human malfeasance, such as a hacker; or human error, such as an operator who accidentally deletes a critical file. 43% of firms that suffer a major data loss go out of business. The second reason why disaster preparedness should be a concern is that, according to the Disaster Recovery Journal, 43 percent of firms that suffer a major data loss go out of business because of it. Thus, you should be concerned because the very future of your business may depend on the Disaster Recovery choices that you make today. Finally, you should take another look at your Disaster Recover strategies, because today's environment has increased the risks that you face and new technologies now offer dramatic new opportunities to improve your disaster preparedness at an affordable price. The remainder of this report examines in more depth the issues surrounding tape versus disk Disaster Recovery alternatives. The Trouble with Tape The majority of companies still depend on tape as their primary or even sole method of backing up data to protect vital information assets from a disaster that may strike a data center. The biggest reason for the dominance of tape is cost. According to Gartner Group, in 2002 the typical cost of enterprise disk storage was US$110 per gigabyte, versus $11 per gigabyte for tape. However, because disk costs are dropping significantly faster than tape costs, this disparity is declining rapidly. The gap has already fallen to the point where, in many cases, disk can affordably replace tape. Tape is also much more portable than magnetic disk. After an enterprise copies all of its data from disk to backup tapes, it can send the tapes across town at a very low cost. For not much more, it can hand them to a courier for delivery across the country. Putting distance between the primary data source and the backup tapes minimizes the probability that a single disaster will destroy both. The greater the distance, the stronger the safeguard will be. However, tape is not the only way to store data remotely. A glut of telecommunications bandwidth and increasing fiber optic efficiency mean that is now easier, faster, and much less expensive than ever before to transmit even large amounts of data to disks at remote recovery centers. Lengthy Recovery Times The benefits of tape end there. While throughput speeds for all media have increased greatly in recent years, tape is still considerably slower than disk, meaning that it takes much longer to reload data from tape than from disk. The fastest tape drives currently on the market provide throughput rates of about 30 megabytes per second, less than half the throughput offered by the newer models of low-cost disk drives. 3

4 Looking just at the time required to reload one terabyte of data, recovering from tape at a rate of 30 megabytes per second would take more than nine hours. Slower tape drives would, obviously, require longer. Then, consider the time required to: Secure the use of a system at another site. Transport a backup tape to that site. Mount the tape or each of a series of tapes on the drive. Copy the data and applications from tape to disk. Reconfigure the systems. It may take days to be up and running after a disaster when tape is the backup medium. However, that tells only part of the story. In the early days of business computing, companies typically saved full backups of all of their files nightly. As databases grew in size, this became impractical. Instead, a typical backup cycle may now involve a full backup once a week, taken on the weekend. During the week, the company may run nightly "incremental" backups, which save only those files or portions of databases that changed since the last full or incremental backup. If only a small percentage of a company's data changes each day, which is often the case, incremental backups greatly reduce the time required to perform the nightly backup processes. However, after a disaster, when the business is struggling to get back on its feet as quickly as possible, this approach may significantly increase the time required to restore access to its data. In the past, when every backup was a full backup, if a disaster struck on Friday, an organization would have to load only Thursday's backup tapes to recover its data. Now, when using a weekly full and nightly incremental backup strategy, to recover from a Friday disaster, the IT staff must first load the tapes from the weekend. Then, they have to load each of Monday's through Thursday's incremental tapes in turn to bring the backup server up-to-date as of the previous night. Thus, it may take days to be up and running after a disaster when tape is the backup medium. Such a lengthy delay in restoring operations can be devastating, putting a business at risk for great financial losses and perhaps even permanent closure. Lost Data How much data are you willing to lose in the event of a disaster? The gut reaction in most companies may be "zero," but this is not possible when using tape as a backup medium. Tape captures the state of a company's data at a point in time, typically sometime in the middle of the night. If a company finishes its nightly backup at midnight, ships the tape offsite and later suffers a disaster that destroys its data center at 11:59 pm, it will lose a full day's worth of data if that tape is the only offsite backup medium. As companies move toward doing more of their business online, without generating any paper, such data may be lost forever. Even when paper records of transactions are still being kept, they may well be destroyed right along with the data center if they are in the same office. Since a disaster can strike at anytime during the day, a company that relies on nightly tape backups as its sole backup source must be willing to accept that, statistically, an average of 12 hours worth of data will be loss in a disaster. Since backup jobs can take several hours to complete, unless the organization halts business operations while creating the 4

5 backup tape, a backup job that finishes at midnight will save some data that changed well before that. What's more, it will take an operator some time to package up the tapes and put them into a courier's hands for offsite delivery. If a disaster should strike during that time, the job that created the most up-to-date surviving backup tape will have started considerably more than 24 hours prior. Attempts to restore data from tape failed as much as 70% of the time. There is a further risk of data loss, beyond losing information that is not yet backed up to tape. That risk stems from the reliability of the backup tapes. People who have never had to depend on tape to recover lost data generally consider it a very reliable medium. It is not. In fact, one study found that attempts to restore data from tape failed as much as 70 percent of the time. Tapes and drives degrade, sometimes leaving the data on backup tapes unrecoverable. When spinning up a series of incremental backups, the closest viable recovery point is represented by the last successful tape. In the previous scenario where a disaster occurs on Friday, just before the next full weekly backup, if Tuesday's incremental backup fails to restore properly, the business has no choice but to restart using Monday's data. The loss of several days of information in a disaster can cause multiple serious business problems that only add to the enormity of the crisis at hand. Business Disruptions Tape-based backup solutions also tend to be more disruptive than disk-based approaches. When using tape, organizations typically create a full backup of their databases and other files at least once a week and possibly daily. Modern backup utilities offer a "savewhile-active" feature that allows operations to continue while the backup job runs. Nonetheless, since the backup job tries to capture all of the data in what are likely exceptionally large files as fast as it can, disk bandwidth and processor utilization become bottlenecks. Operations can continue, but will likely be impaired significantly. This might be acceptable during "off-hours" in companies that run a nine-to-five, five-daya-week business, but it is unacceptable in the 24x7 organizations that are now more prevalent because of the Internet, globalization and competitive pressures. Unreliable Strategies, Processes and Technologies The chasm between "supposed to work" and "does work" is often wide and sometimes unbridgeable. Most organizations that use tape backup strategies depend on a thirdparty recovery facility to provide a server when disaster strikes. Due to the time required to load a full backup from tape at the facility and the cost involved, recovery procedures are rarely, if ever tested. That leaves open the questions: Are the backup procedures truly capturing all of the user and system data needed to restore a functioning system at the recovery site? Will all of the equipment (servers, storage devices and other peripherals) at the backup site fully support the organization's current application needs and are the systems and peripherals adequately sized? Will the organization's recovery procedures actually produce a functioning, accurate system in a timely fashion? While the use of tape as a backup medium does not negate the possibility of regular testing, it makes it difficult, time consuming and costly, thereby reducing the likelihood that it will be done. 5

6 The High Availability Alternative On the high end, one alternative to tape for Disaster Recovery is to deploy a High Availability solution that maintains two or more fully redundant servers in geographically separated locations. Achieving this involves the use of advanced software, such as MIMIX, from Lakeview Technology, to first copy all data, applications and system objects from the primary system to the remote backup. From that point, the solution keeps the remote system continuously updated by capturing any changes made to the primary system and copying and applying them to the backup system in near real-time. A High Availability solution may be more than an organization may need. Using this approach, you can recover almost immediately by switching to an already active and current replica of your disabled or destroyed production server. If the High Availability solution includes the capability to monitor primary system status and automatically switch users to the backup when necessary, there may be little or no noticeable downtime when a disaster mandates a switch to the recovery server. Since High Availability solutions replicate all changes in near real-time, the only loss will be data that was not yet replicated due to delays (latency) in the replication processes, delays that which rarely extend beyond a few seconds. Some High Availability solutions can eliminate even this minimal data loss by writing data changes to the backup system before writing them to the primary system. The drawback of implementing a High Availability solution only to achieve Disaster Recovery capability comes not from any failings in the effectiveness of the solution it is near foolproof but rather from being more than an organization may need. Implementing High Availability just to assure Disaster Recovery can be costly when you consider software license fees, the increased load that the solution places on the system and the need to design and configure a solution that meets your unique needs. These costs are more than some companies can justify when the nature of their business is such that they can accept a small amount of downtime and some risk of a little lost data. These companies need only the ability to recover from a disaster as quickly and as completely as possible a capability available in new, economical disk-based solutions, such as MIMIX dr1. Guidelines for Choosing an Alternative When considering a Disaster Recovery solution, ask yourself the following questions: How much data can we afford to lose before the impact would become unbearable? Considering all factors lost revenue, lost productivity, legal ramifications, the cost of remedial actions, and so on how much will each hour of downtime resulting from a disaster cost us? Taking into account our Disaster Recovery objectives, how much of an investment in software and staffing are we willing to make for each level of disaster preparedness offered by the available options? Answering these questions and surveying the available options in the marketplace will provide a guide to the level of disaster preparedness you can justify in your organization. If you decide that tape backups impose a greater risk of data loss and slower recovery times than your organization is willing to accept, but you cannot cost-justify a full High Availability solution, then you should consider a disk-based Disaster Recovery solution. 6

7 Characteristics of a Superior Alternative Having made that decision, you must choose from among the available alternatives. Key issues to consider include: The solution must meet or exceed your data recovery time (RTO) and acceptable data loss (RPO) guidelines at a price that, given your organization's risk levels and potential liabilities, will provide proper protection and an adequate return on investment. The solution must support your organization's existing information technology platforms. The solution should be flexible enough to accommodate your evolving future needs. MIMIX dr1 provides a complete disk-based recovery solution, at an affordable cost. The solution must be reliable. Since you will be betting your company's future on it, it must work without fail. The solution should be easy to implement. Since cost is one of the reasons for choosing a disk-based Disaster Recovery option rather than a complete High Availability solution, implementation should not consume significant resources. The vendor should be financially stable enough to continue to support its product into the foreseeable future. And, of course, the value delivered must at least justify its price. For organizations running IBM eserver iseries servers, one such solution is MIMIX dr1, from Lakeview Technology. A Breakthrough Solution: MIMIX dr1 MIMIX dr1 is truly a breakthrough solution. While other disk-to-disk backup alternatives exist, they usually treat disk as "virtual tape". Using one of these "virtual tape" options, recovery may be faster than when using tape, but the data may be no more up-to-date than what was stored on tape and data recovery may be only marginally easier than it was for tape. MIMIX dr1 goes much further. MIMIX dr1 updates data on a recovery (backup) server periodically throughout the day, to provide a complete disk-based recovery solution, at an affordable cost. Minimize the amount of data lost to a disaster. MIMIX dr1replicates data changes as they happen, from a production server to a special cache, called a Recovery Point, on a recovery server. Then, when activity on the production server reaches a natural lull, such as when employees are away at lunch or whenever database activity pauses, MIMIX dr1 captures the Recovery Point and starts a new cache file. After MIMIX dr1 applies the captured transactions to the recovery server, the recovery server is a replica of the production server at the point when database activity paused. MIMIX dr1 also allows you to set the Replication Policy, which is the minimum time that dr1 should wait before looking for a pause in activity and capturing the current Recovery Point. For most environments, setting the Replication Policy to between two and four hours provides optimal protection, but you can set it to as little as 30 minutes to keep critical files more current. 7

8 During long busy times, MIMIX dr1 checks continuously until activity pauses. Whenever the time since the last Recovery Point capture exceeds the Replication Policy, MIMIX dr1 will alert you, providing the option to pause operations manually, if necessary. You can run multiple instances of MIMIX dr1 at the same time, each independently protecting a particular application or business process, thereby increasing the likelihood that MIMIX dr1 will find a lull within each instance that meets or comes close to your Replication Policy. Reduce implementation costs. With an intuitive online wizard, MIMIX dr1's user interface makes it easy to set up a customized "Replication Pattern", which is the configuration file that identifies which files and objects MIMIX dr1 will replicate. MIMIX dr1 does not rely upon journaling. MIMIX dr1's installation wizard allows quick self-installation across multiple systems, using straightforward, intuitive navigation. MIMIX dr1's color-coded status icons and clear, complete messages allow you to manage easily all operations across all systems in your replication environment, from starting and ending replication to viewing messages and updating your Replication Patterns when new files and objects are added to your system. Minimize recovery time and effort. With MIMIX dr1, your backup environment is ready at all times to take over as the production environment, with a minimum of effort, should disaster strike your primary system. Procedures for bringing your recovery server online are straightforward and well documented in MIMIX dr1's on-line help. Reduce overhead costs. Because MIMIX dr1 does not rely upon journaling, it does not force you to turn journaling on. Instead, using replication algorithms developed by Lakeview Technology, MIMIX dr1 continually checks for production system changes and updates the Recovery Point cache, in real-time. Increase flexibility. MIMIX dr1 can back up data to a remote server, a local server or even to another partition within a single server. However, the latter two options, local and partitioned backups, are not true Disaster Recovery options. If a disaster destroys the data center, it will likely destroy both local servers and all partitions within a single server. While the local options may not provide a complete Disaster Recovery solution, because of the significantly lower costs involved, some organizations may find these alternatives adequate for their needs. Local backups will provide protection against incidents that destroy a single set of disks, but not the whole data center. Under these scenarios, backup tapes should still be prepared and sent offsite to protect against total, unrecoverable data loss in the case of a more widespread disaster. Since the backup server or partition will contain a complete set of your data up to the last Recovery Point, you can use it as a source for backup tapes in order to avoid any disruption of operations on the primary server or partition. 8

9 Summary Business depends on data being available. Without a comprehensive and reliable backup and recovery solution, a disaster that destroys critical data could, without exaggeration, bankrupt your organization. Tape provides an extremely economical means to backup data, but it suffers serious flaws. Being a slow medium, data recovery takes a long time, possibly longer than an organization can survive without its data and systems. In addition, since tape backup procedures capture data as of a point of time, rarely more frequently than once a day, a significant volume of new data may be lost in the event of a disaster. What's more, tape is a particularly fallible medium, raising the potential for the loss of even more data. Alternatives do exist, but some, such as High Availability solutions, may be more than some smaller or less vulnerable companies need and, more importantly, more than they can afford. Organizations looking for a middle ground a disk-based solution that avoids the pitfalls of tape without the costs of a full High Availability solution should add MIMIX dr1 to their disaster recovery consideration set. For more information on MIMIX dr1 and to view a product demo, visit 9

10 About Lakeview Technology Lakeview Technology is a leader in infrastructure software and services, specializing in High Availability, Disaster Recovery, Clustering and Data Replication. Lakeview s solutions enhance the customer s information enterprise by making business information highly available and accessible to decision makers. By supporting any application in OS/400, Windows, UNIX and Linux operating environments, Lakeview offers customers a single vendor of choice who can simplify the complexity of the IT infrastructure and deliver high ROI within 12 months. Companies around the world have trusted their information to Lakeview Technology s MIMIX and OmniReplicator software for over a decade. Customers range from Fortune 100 to medium and small businesses across all industries. Headquartered near Chicago, Illinois, Lakeview serves customers from offices in the U.S., Europe and Asia and through an extensive partner network. For more information, please visit or call USA Belgium Hong Kong UK Germany Lakeview Technology Inc South Meyers Road Suite 600 Oakbrook Terrace, IL USA Info@lakeviewtech.com Copyright 2004 Lakeview Technology Inc. All Rights Reserved. MIMIX and OmniReplicator are trademarks of Lakeview Technology. All other trademarks are property of their respective holders. M-ER-DR1-0104