Disk-to-disk backup: pass the data please. (Tape/Disk/Optical Storage).
From the earliest days of electronic data, backup storage A storage device used to hold copies of data for backup and recovery. In the IT world, tape drives and tape libraries have been the traditional backup storage medium; however, magneto-optic (MO) and other optical discs as well as regular magnetic disks are also used. See LAN free backup. media was a "whatever performance at the lowest cost" choice, a theory that historically pointed to tapebased backup. But now the evolution of technology is changing the relationship between cost and performance and, much like punch cards A storage medium made of thin cardboard stock that holds data as patterns of punched holes. Each of the 80 or 96 columns holds one character. The holes are punched by a keypunch machine or card punch peripheral and are fed into the computer by a card reader. and paper tape, tape-based backup carries a lot of hidden costs and hassles that make it increasingly less than ideal. For this reason, end-users are increasingly looking for Looking for
In the context of general equities, this describing a buy interest in which a dealer is asked to offer stock, often involving a capital commitment. Antithesis of in touch with. alternatives to traditional backup-and-restore methods, and disk-to-disk backup is looking more and more promising as a way to eliminate backup hassles, improve backup performance, and reduce overall costs.
According to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. the Gartner Group (company) Gartner Group - One of the biggest IT industry research firms.
Address: Connecticut, USA. , backup remains the single most costly storage administration task. Managing a tape backup 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. system requires complex configuration, continuous monitoring and frequent tuning. Tape libraries need to be loaded with media, tapes need to be manually tracked and moved around, tape drives frequently fail and tape libraries need constant maintenance and attention. Although tape drive capacity and performance are improving, the improvement is not keeping pace with significant advances in disk technologies or the increasing amount of data being stored on a typical network. These problems are compounded because as the amount of data grows, tape devices and their 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 performance do not scale appropriately. Couple this with a lack of skilled IT resources and the ever-increasing demand for high data availability Refers to the degree to which data can be instantly accessed. The term is mostly associated with service levels that are set up either by the internal IT organization or that may be guaranteed by a third party datacenter or storage provider. , and the result is that backups place an immense burden on IT departments.
Enterprise backup and recovery means more than disaster recovery to today's enterprise. The rapid restoration of damaged files or file systems (including database files) is critical to maintaining routine business operations Business operations are those activities involved in the running of a business for the purpose of producing value for the stakeholders. Compare business processes. The outcome of business operations is the harvesting of value from assets . The majority of real-life recoveries in our current IT environment are not "full system disaster recovery" restores; instead, they are partial file system or even single-file restores required to quickly bring critical applications back online and preserve business as usual.
Historically, disk technology has been orders of magnitude more expensive than tape media. Tape has therefore been used for data intensive applications such as backup and archival. Times have changed. Over the last ten years, the Years, The
the seven decades of Eleanor Pargiter’s life. [Br. Lit.: Benét, 1109]
See : Time cost of disk has plummeted; it is highly cost-effective now, and its cost advantages over tape will continue to grow rapidly. When it comes to the basic cost of media, tape has lost its edge.
Without even taking the cost of a tape drive into account, it is interesting to compare the costs of disk versus tape media. Only ten years ago, disk cost $1,000 per GB and tape media cost $10 per GB. The recent announcement of a 300GB 3.5inch disk available this year will, for the first time, mean that the per-gigabyte cost of disk will be less than that of tape media alone. More significantly, it shows that in only ten years the cost of disk has declined over 1 000X compared to tape media, which has only declined by l0X. For some time it has been possible to buy a powerful, functional disk array for much less than the cost of an equivalent tape library.
ATA drives The formal name for an IDE drive. See IDE. today cost about 1 to 1.5 cents per megabyte One million bytes, or more precisely 1,048,576 bytes. Also MB, Mbyte and M-byte. See mega and space/time.
(unit) megabyte - (MB, colloquially "meg") 2^20 = 1,048,576 bytes = 1024 kilobytes. 1024 megabytes are one gigabyte. , compared to 3 to 5 cents for 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 6 to 8 cents for Fibre Channel drives. Tape is typically a penny or less per megabyte, but the cost of media to keep up with storage demands can and does inflate inflate - deflate the overall expense. New, higher capacity ATA drives are imminent and anticipated to bring ATA drive costs down to one-half cent per megabyte. Additionally, today's ATA RAID Using ATA (IDE) drives in a high-performance and/or fault tolerant configuration. See RAID. leaders are delivering subsystems that bring the cost of ATA (1) (AT Attachment) The specification for IDE drives. See IDE.
(2) See analog telephone adapter.
ATA - Advanced Technology Attachment RAID-based disk storage below $3 a gigabyte.
So Much Data, So Little Time
Beyond the changing cost-percapacity of storage media, disk storage can reduce the operational and administrative costs administrative costs,
n.pl the overhead expenses incurred in the operation of a dental benefits program, excluding costs of dental services provided. of backup storage. The slow seek time, throughput performance, media characteristics and sequential access In computer science, sequential access means that a group of elements (e.g. data in a memory array or a disk file or on a tape) is accessed in a predetermined, ordered sequence. Sequential access is sometimes the only way of accessing the data, for example if it is on a tape. nature of tapes and tape drives causes complexity, unreliability and limitations within existing backup systems Noun 1. backup system - a computer system for making backups
ADP system, ADPS, automatic data processing system, computer system, computing system - a system of one or more computers and associated software with common storage . Compared to tape, disk offers enormous benefits in terms of performance, reliability and ease of administration.
Slow Tape Seek Time: Optical media and slow-loading tape drives, the solution typically chosen by most nearline storage Nearline storage (where Nearline is a contraction of Near-online) is a term used in computer science to describe an intermediate type of data storage. It is a compromise between online storage (constant, very rapid access to data) and offline storage (infrequent users, provide access times that range from 10 seconds to more than 20 seconds, including 5 to 10 seconds for a robotic media exchange. In contrast, disk systems provide nearly instantaneous access, measured in just milliseconds.
Throughput and System Performance: The fastest tape drives today perform at transfer rates of 30MBytes/sec. Even desktop class ATA disk drives achieve 40-50MB/sec transfer rates. And the newest generation of enterprise class Serial ATA See SATA.
Serial ATA - Serial Advanced Technology Attachment drives is delivering upwards of 60-75 MB/sec performance-and doing it at prices still one-half that of SCSI drives. In addition, restoration is significantly faster because access to data takes milliseconds compared with minutes in a tape library.
Media Characteristics and Functionality: Ironically, although the vast majority of current information protection is performed by backing up data onto some type of magnetic media, tape backup and restoration often does not work and creates a huge headache for most businesses. Typically, IT departments spend between 20 and 30 percent of their manpower dealing with tape backup problems. Over 30 percent of all storage problems stem from tape backup systems. A recent study found that while tape backups are used extensively, restoring data from a tape backup system fails an astounding a·stound
tr.v. a·stound·ed, a·stound·ing, a·stounds
To astonish and bewilder. See Synonyms at surprise.
[From Middle English astoned, past participle of astonen, 70 percent of the time. The reasons for such an alarming rate of failure range significantly--and may vary from bad tapes or tape drives to the inability to find the backup tapes or careless processing by IT staff. Tape drives and physical tape media can be unreliable and frequently cause backup failure. Conversely, disk-based backup makes use of highly reliable Serial ATA disks coupled with RAID hardware that provides multiple layer s of data protection combined with extremely high MTBF (Mean Time Between Failure) The average time a component works without failure. It is the number of failures divided by the hours under observation.
MTBF - Mean Time Between Failures numbers for strong data protection. The maintenance of the disk-based backup solution is far simpler than a tape library, as there are no robotic arms or tape drives. Consequently, maintenance costs for disk-based solutions are far lower than for equivalent tape libraries.
Sequential Versus Random Access and Faster Data Recovery Smooth recovery from operational or data disasters is a competitive necessity and time-to-recovery directly affects an organization's bottom line. With the slow performance of tape-based backup, restoring operations can take many hours even under optimal circumstances. While most failures only involve a limited number of files, the entire backup set must be restored from tape to disk, regardless of whether a full restore is needed or not. Since data on tape cannot be individual data can only be restored, copied and used after a complete, lengthy extraction.
On the other hand, the high throughput and instant access provided by disk-based backup results in much faster data recovery than from tape. Disk-to-disk backup arrays can also restore an individual file or set of data in seconds or minutes without the slow triple step "restore-copy-delete" process. By directly accessing and restoring individual files, it's possible to restart systems in minutes using disk-based backup, dramatically reducing the business impact of emergencies or other unplanned system failures.
Key Features of ATA RAID-Based Disk-to-Disk Backup
Accelerates Data Backup: Backing up primary storage to disk-based backup storage is two to four times faster than tape, shrinking the backup window down to a few hours or less.
Speeds Data Recovery: Administrators can rapidly restore backed up business-critical data much faster than from tape, almost instantly restoring individual files and folders with no tape load time.
Improves Backup Process: Time-consuming tape backups are offloaded from primary storage; backup of several systems is automatically consolidated.
Provides Online Access to Archived Data: Reference and archive data can be quickly retrieved and maintained on cost-effective storage.
Where Did All of This Data Come From?
In today's storage environments, applications being used and data access needs significantly affect storage media decisions. For applications where readily available data would be beneficial, using disk for nearline backup storage provides added application benefits. One such scenario is the overflow of reference data, actually a driving force that favors ATA disk-based storage. According to research by the Enterprise Storage Group (ESG ESG Enterprise Strategy Group (Veritas)
ESG Emergency Shelter Grant (Florida, USA)
ESG Expeditionary Strike Group
ESG Electronic Service Guide (used in DVB) ), reference information--such as legal documents, e-mail, presentations, source code, Web content, CAD/CAM CAD/CAM
in full computer-aided design/computer-aided manufacturing.
Integration of design and manufacturing into a system under direct control of digital computers. designs, medical images, photographs, geophysical data and historical documents--represented 37 percent of all stored data in 2001. By the end of 2005, ESG predicts reference information will represent 54 percent of all new information, a significant amount of information and likely to benefit from nearline availability.
Similarly, many IT operations use tape-based solutions for long-term archiving. Disk-based backup is typically not considered a feasible solution for records that must be archived for years or on a permanent basis. Even in an environment where records are being archived on tape, many IT departments will use disk-based storage as a staging server A server used to temporarily show certain users new and revised Internet and/or intranet pages before they are put into production. , recording multiple backup cycles before being archived on tape. In this implementation, while tape may prove useful in maintaining archived records, actual restorations are typically made from data that was saved in the first two or three backup cycles, providing another clear justification for a disk-based solution in the system.
Pass the Data. Hold the Check
Disk-to-disk backup is now a viable enhancement, or alternative, to disk-to-tape operations--due to the emergence of ATA-based disk arrays that are lower in price than tape libraries, as well as the performance advantages of disk drives over tape. Tape remains a strong contender for long term data archiving and off-site storage. System administrators who use disk-to-disk backup can expect a 2X to 3X performance improvement in backup-and-restore operations compared to traditional tape systems. The performance improvements of disk-to-disk operations are directly related to the dramatically faster speeds of ATA drives. And since disk drives are random access devices, data can be written and read (backed up and restored) on a file-by-file level or on whole data sets far faster than tape. Restores can be completed in seconds rather than hours, and the restore risks and dependencies associated with tape are eliminated with a disk-to-disk approach. After data is backed up to disk, further protection steps can be tak en, including cloning or data staging from the disk to tape.
Declining disk drive costs and improved speed are key motivations for end-user adoption of disk-to-disk backup. Related benefits include improved end-user response times (due to faster restore rates) and decreased demand on IT staff resources because disk arrays do not require operator intervention. Improved reliability of disk drives--and the fact that disk-to-disk backup makes it easier to do more frequent backups which ultimately increases data protection--are also critical factors allowing more organizations to improve their backups and restores. And that is just plain smart business. Pass the data please.
Andy Newbom is product marketing manager, Advanced Storage Group, at Promise Technology, Inc. (Milpitas, Calif.)