This Blog talks about the ways and the significance of backup.
Storage is energetic to any computer system. It is doubly vital to an ERP system which serves as the memory for the business. Lose that memory and you’re out of business.
Backups are copies of all the important data on your system taken and preserved in such a way that you can recover your data no matter what happens. Making backups and being sure you have good ones is a best business practice. Typically an SAP system will have one or more storage administrators to take care of storage and backup systems. However as manager of the SAP system it’s important that you understand the basics of backup because it is so intimately connected with running a successful SAP system
Basically, ‘backup’ refers to three different things, only one of which is truly backup. There is short-term backup, which preserves a copy of the document for a short time, typically a week or two. There is true backup which saves a copy for a year or so. Then there is archival backup which saves important data permanently – or at least for five years.
These three serve very different purposes. Short term storage is designed to protect files from corruption or deletion, usually accidental and generally within a short time of creation. It is marked by very fast restore times and is the most commonly used form. True backup is designed to keep a copy of the files available for a longer period of time for restoring data. It may last for a year or even longer. Archival storage is designed to save important data permanently. Short term storage usually relies on storage on the active disk or disks. True backup uses longer term disk storage, often on slower, less expensive disks or on tape. Archival storage is typically on magnetic tape, although hard disk arrays are becoming more common. Archival material is often moved off site to a secure facility for permanent storage.
The three differ in how quickly they can recover the data committed to them. Short-term storage can usually get the data back in seconds. True backup takes longer, sometimes as much as a day or so if the backups have been taken off site. Archival storage may take a day or two to recover
Backups have to balance speed, cost and security. Short term storage is on the server’s hard disk and has a very low cost, but also low security. True backup is stored on a separate disk array or magnetic tape cartridge, usually dedicated to backup. It takes somewhat longer to recover, even when the storage media are kept on site. It is more secure than the short term storage and more costly. Archival storage stores large quantities of data on magnetic tape or special disk arrays. It is the slowest to get back and the most secure. Although the tape drives and tape are expensive, they are the cheapest kind of storage on a per megabyte basis.
Short term storage is usually created in the background as the user works. It records data almost on a keystroke by keystroke basis so the information is available for restoration immediately. It typically comes as a component of operating systems like Windows.
True backup is slower to create, usually taking the storage in chunks and transferring it from the working and disk to the backup disk or tape. It requires a dedicated backup disk or disks (in an array) or tape drive. Often backups are only taken once a day or even longer because backups slow down the system quite noticeably.
Archival storage is done by disk to disk or disk to tape transfers in the background. Usually the files are automatically edited so that only the important ones are preserved. If tape is used, it is not unusual to take the tapes off site to protect them in some sort of secure storage.
All this is important to the SAP manager because it has a direct impact on how day-to-day operations are performed. Since SAP systems tend to be heavily used you want a backup system that puts the minimum performance penalty on your ERP server.
The rule of backup is to always make at least one copy of all important data – essentially everything – and to store it securely.