This manual cannot hope to keep up with the capabilities of various devices on each operating system. The Microlite Web Site (http://www.microlite.com) has a full support section, plus a
Device Compatibility section under Device Support Tables. Please see the web site for
2 - Anatomy of a BackupEDGE Backup
Understanding what “Backup” means is the key to understanding how BackupEDGE works.
In its simplest form, a backup means “take these data and make a copy of them over there”. This is the method used by the UNIX tar, cpio, and dump commands for years: data (in the form of
individual files) are copied to a tape, and can be restored from a tape. There is no notification or summary of results, no easy way to schedule backups regularly, and rarely any way to verify that the operation actually worked. To these programs, a backup is an action: that of copying data. This works well, as long as your backup strategy is simple, your data is easy to access, and your tape drive is reliable. Unfortunately, these assumptions are far too restrictive for most production environments.
Ultimately, anything that does a backup must “copy ... them over there”, at some level. However, that is only the beginning of what the average system administrator needs to protect the data in his or her care. To be truly useful, a backup solution must allow easy management of what data is copied, when it is copied, and to what Device is it sent. It must determine, reliably, the success or failure of the copy operation, and produce reports on the results. It must provide a clear path to restoring that data later, with a minimum of fuss or hassle. In short, protecting data in a
production environment is a process, only a small part of which is the single action of copying data from one storage system to another.
BackupEDGE provides this process, which is described in the rest of this manual. If you usually
think about a backup as an action, then by adjusting that view slightly, you may be able get much more out of BackupEDGE.
In BackupEDGE, typically a Backup happens when a Scheduled Job creates a backup in a
Sequence of a Domain to a particular a Resource (which represents some physical Device). That
seems very complicated when compared to the action of copying files to tape, but the added complexity is only a superficial side-effect of viewing a backup as a process. Let’s break it down and show you how simple, logical, and powerful it is.
• The Device is the physical thing, such as a tape drive or NAS, that you will be using to store data. In some cases, a Device can also be a disk file. Device may be locally attached or network accessible.
• The Resource is the BackupEDGE software representation for your storage Device. It knows all about how to control the Device, write to it, and read from it, and erase or overwrite things stored on it. It records the appropriate settings for the Device to force data to be written and managed in a consistent way.
• The Domain defines data that is to be protected by a backup, and how BackupEDGE should treat that data. It specifies which files or filesystems are to be treated specially, and what if any special actions are to be taken before and after the backup to prepare those files to be archived. You may specify as many Domains as you like to allow BackupEDGE to protect different subsets of your data separately. A Domain stands in contrast to “a list of files” as seen by tar or cpio, since it includes information about how the data in those files are to be
accessed beyond simply the filename that is used to find that data.
• The Sequence defines and tracks a unique group of Master, Differential and Incremental
Backups for exactly one Domain. To maintain, for example, on-site and off-site backups that
NOTE: BackupEDGE establishes defaults during the installation process that provide very
useful on-site full-system backups and reports without a working knowledge of all the information and concepts described below. In particular, it selects defaults that emulate the action “backup up every file every night”. The more you know, however, the better you will be able to extend the usefulness of the product.
protect your entire system, a different Sequence would be used for each (although both
Sequences would refer to the same Domain, since both protect the same data). This keeps the
on-site and off-site backups separate, which is especially useful when performing Differential or Incremental Backups. When a scheduled backup is performed, it contributes a backup to exactly one Sequence, of the Domain referred to by that Sequence. In contrast, the action of copying data generally keeps no records at all!
• The Scheduled Job is a complete specification for a backup. It contains a list of one or more
Domains to be backed up, allows selection of a Sequence for tracking, and defines which Resource will be used for it. It also specifies:
- when the backup is to be done.
- what type of Verify pass (if any) is to be run.
- whether the backup should be indexed for Fast File Restore.
- whether the backup should or can be made bootable for Disaster Recovery. - when the archive created may be erased /or overwritten (expiration).
- promotion strategies, which define the circumstances under which a Differential Backup may be promoted to a Master Backup, or an Incremental Backup to a Differential Backup. - autoloader medium selection.
- media unload / eject strategies.
It also records whom to notify if the backup passes, and whom else to notigy if the backup fails. Notification may be by printer, text email, HTML email, or SMS short text message. • The Quota defines the maximum amount of data that can be written to a disk-based storage
Resource such as a cartridge disk drive (FSP), network attached storage device (URL), or to
the Amazon S3 internet storage cloud (AWS).
Each of the major BackupEDGE concepts has been designed and organized to control its own part of the backup process in logical steps. Let’s break them down a little further.