Disk staging

Last updated

Disk staging is using disks as an additional, temporary stage of backup process before finally storing backup to tape. [1] Backups stay on disk typically for a day or a week, before being copied to tape in a background process and deleted afterwards.

In information technology, a backup, or data backup, or the process of backing up, refers to the copying into an archive file of computer data that is already in secondary storage—so that it may be used to restore the original after a data loss event. The verb form is "back up", whereas the noun and adjective form is "backup".

Magnetic tape data storage is a system for storing digital information on magnetic tape using digital recording. Modern magnetic tape is most commonly packaged in cartridges and cassettes. The device that performs writing or reading of data is a tape drive. Autoloaders and tape libraries automate cartridge handling. For example, a common cassette-based format is Linear Tape-Open, which comes in a variety of densities and is manufactured by several companies.

Contents

The process of disk staging is controlled by the same software that performs actual backups, which is different from virtual tape library where intermediate disk usage is hidden from main backup software. Both techniques are known as D2D2T (disk-to-disk-to-tape).

A virtual tape library (VTL) is a data storage virtualization technology used typically for backup and recovery purposes. A VTL presents a storage component as tape libraries or tape drives for use with existing backup software.

Restoring data

Data is restored from disk if possible. But if the data exists only on tape it is restored directly (no backward-staging on restore).

Reasons

Reasons behind using D2D2T:

In computer data storage, data striping is the technique of segmenting logically sequential data, such as a file, so that consecutive segments are stored on different physical storage devices.

Tape drive data storage device that reads and writes data on a magnetic tape

A tape drive is a data storage device that reads and writes data on a magnetic tape. Magnetic tape data storage is typically used for offline, archival data storage. Tape media generally has a favorable unit cost and a long archival stability.

See also

  1. Preston, W.C. (2007). Backup & Recovery: Inexpensive Backup Solutions for Open Systems. O'Reilly Media, Inc. pp. 219–220. ISBN   978-0-596-55504-7 . Retrieved 8 May 2018.

Related Research Articles

Computer data storage technology consisting of computer components and recording media used to retain digital data

Computer data storage, often called storage or memory, is a technology consisting of computer components and recording media that are used to retain digital data. It is a core function and fundamental component of computers.

RAID is a data storage virtualization technology that combines multiple physical disk drive components into one or more logical units for the purposes of data redundancy, performance improvement, or both. This was in contrast to the previous concept of highly reliable mainframe disk drives referred to as "single large expensive disk" (SLED).

A disk image, in computing, is a computer file containing the contents and structure of a disk volume or of an entire data storage device, such as a hard disk drive, tape drive, floppy disk, optical disc, or USB flash drive. A disk image is usually made by creating a sector-by-sector copy of the source medium, thereby perfectly replicating the structure and contents of a storage device independent of the file system. Depending on the disk image format, a disk image may span one or more computer files.

Copy-on-write, sometimes referred to as implicit sharing or shadowing, is a resource-management technique used in computer programming to efficiently implement a "duplicate" or "copy" operation on modifiable resources. If a resource is duplicated but not modified, it is not necessary to create a new resource; the resource can be shared between the copy and the original. Modifications must still create a copy, hence the technique: the copy operation is deferred to the first write. By sharing resources in this way, it is possible to significantly reduce the resource consumption of unmodified copies, while adding a small overhead to resource-modifying operations.

Quantum Corporation is a manufacturer of data storage devices and systems, including tape drive and disk-based systems. The company's headquarters is in San Jose, California.

File system concrete format or program for storing files and directories on a data storage device

In computing, a file system or filesystem, controls how data is stored and retrieved. Without a file system, information placed in a storage medium would be one large body of data with no way to tell where one piece of information stops and the next begins. By separating the data into pieces and giving each piece a name, the information is easily isolated and identified. Taking its name from the way paper-based information systems are named, each group of data is called a "file". The structure and logic rules used to manage the groups of information and their names is called a "file system".

A remote, online, or managed backup service, sometimes marketed as cloud backup or backup-as-a-service, is a service that provides users with a system for the backup, storage, and recovery of computer files. Online backup providers are companies that provide this type of service to end users. Such backup services are considered a form of cloud computing.

Unitrends Inc., a Kaseya company, is a US-based company specializing in backup and business continuity.

Veritas Backup Exec is a data protection software product designed for customers who have mixed physical and virtual environments, and who are moving to public cloud services. Supported platforms include VMware and Hyper-V virtualization, Windows and Linux operating systems, Amazon S3, Microsoft Azure and Google cloud storage, among others. All management and configuration operations are performed with a single user interface. Backup Exec also provides integrated deduplication, replication, and disaster recovery capabilities and helps to manage multiple backup servers or multi-drive tape loaders.

In computer science, storage virtualization is "the process of presenting a logical view of the physical storage resources to" a host computer system, "treating all storage media in the enterprise as a single pool of storage."

Hardware virtualization is the virtualization of computers as complete hardware platforms, certain logical abstractions of their componentry, or only the functionality required to run various operating systems. Virtualization hides the physical characteristics of a computing platform from the users, presenting instead an abstract computing platform. At its origins, the software that controlled virtualization was called a "control program", but the terms "hypervisor" or "virtual machine monitor" became preferred over time.

Catalogic DPX is an enterprise-level data protection solution that backs up and restores data and applications for a variety of operating systems. It has data protection, disaster recovery and business continuity planning capabilities. Catalogic DPX protects physical or virtual servers including VMWare, supports many database applications, including Oracle, SQL, SharePoint, and Exchange. DPX supports agent-based or agent less backups. Users can map to and use a backed up version of the database if something goes wrong with the primary version. DPX is managed from a single console and catalog. This allows for centralized control of both tape-based and disk-based data protection jobs across heterogeneous operating systems. DPX can protect data centers, remote sites and supports recovery from DR. DPX can protect data to disk, tape or cloud. It is used for various recovery use cases including file, application, BMR, VM or DR. DPX can spin up VMs from backup images, recover physical servers, bring up applications online from snapshot based backups, it can be used to recover from Ransomware.

In computing, data deduplication is a technique for eliminating duplicate copies of repeating data. A related and somewhat synonymous term is single-instance (data) storage. This technique is used to improve storage utilization and can also be applied to network data transfers to reduce the number of bytes that must be sent. In the deduplication process, unique chunks of data, or byte patterns, are identified and stored during a process of analysis. As the analysis continues, other chunks are compared to the stored copy and whenever a match occurs, the redundant chunk is replaced with a small reference that points to the stored chunk. Given that the same byte pattern may occur dozens, hundreds, or even thousands of times, the amount of data that must be stored or transferred can be greatly reduced.

The subject of computer backups is rife with jargon and highly specialized terminology. This page is a glossary of backup terms that aims to clarify the meaning of such jargon and terminology.

HP Data Protector software is automated backup and recovery software for single-server to enterprise environments, supporting disk storage or tape storage targets. It provides cross-platform, online backup of data for Microsoft Windows, Unix, and Linux operating systems.

NetVault is a set of data protection software developed and supported by Quest Software. NetVault Backup is a backup and recovery software product. It can be used to protect data and software applications in physical and virtual environments from one central management interface. It supports many servers, application platforms, and protocols such as UNIX, Linux, Microsoft Windows, VMware, Microsoft Hyper-V, Oracle, Sybase, Microsoft SQL Server, NDMP, Oracle ACSLS, IBM DAS/ACI, Microsoft Exchange Server, DB2, and Teradata.

Backup-to-disk refers to technology that allows one to back up large amounts of data to a disk storage unit. The backup-to-disk technology is often supplemented by tape drives for data archival or replication to another facility for disaster recovery. Additionally, backup-to-disk has several advantages over traditional tape backup for both technical and business reasons explained later in this article. With continued improvements in storage devices to provide faster access and higher storage capacity, a prime consideration for backup and restore operations, backup-to-disk will become more prominent in organizations.