Книга: Windows Server 2012 R2 Storage, Security, & Networking Pocket Consultant

Figuring out a backup plan

Figuring out a backup plan

It takes time to create and implement a backup and recovery plan. You need to figure out what data needs to be backed up, how often the data should be backed up, and more. To help you create a plan, consider the following questions:

? How important or sensitive is the data on your systems? Knowing the importance of data can go a long way toward helping you determine whether you need to back it up, in addition to when and how it should be backed up. For critical data, such as a database, you should have redundant backup sets that cover several backup periods. For sensitive data, you should be sure that backup data is physically secure or encrypted. For less important data, such as daily user files, you won’t need such an elaborate backup plan, but you do need to back up the data regularly and ensure that the data can be recovered easily.

? What type of information does the data contain? Data that doesn’t seem important to you might be very important to someone else. The type of information the data contains can help you determine whether you need to back up the data, in addition to when and how the data should be backed up.

? How often does the data change? The frequency of change can affect your decision on how often certain data should be backed up. For example, data that changes daily should be backed up daily.

? Can you supplement backups with shadow copies? Shadow copies are point-in-time copies of documents in shared folders. These point-in-time copies make recovering documents easy because you can quickly go back to an older version in case a document is deleted or overwritten accidentally. You should use shadow copies in addition to standard backups, not to replace backup procedures.

? How quickly do you need to recover the data? Recovery time is an important factor in a backup plan. For critical systems, you might need to get back online swiftly. To make this possible, you might need to alter your backup plan.

? Do you have the equipment to perform backups? You must have backup hardware to perform backups. To perform timely backups, you might need several backup devices and several sets of backup media. Backup hardware includes hard disk drives, tape drives, optical drives, and removable disk drives. In most environments, hard disk drives have become the preferred back up media.

? Who will be responsible for the backup and recovery plan? Ideally, someone should be a primary contact for the organization’s backup and recovery plan. This person might also be responsible for performing the actual backup and recovery of data.

? What’s the best time to schedule backups? Scheduling backups when system use is as low as possible will speed up the backup process. However, you can’t always schedule backups for off-peak hours, so you need to carefully plan when key system data is backed up.

? Do you need to store backups off site? Storing copies of backups off site is essential to recovering your systems in the event of a natural disaster. In your off-site storage location, you should also include copies of the software you might need to install to reestablish operational systems.

REAL WORLD Recovery time objective (RTO) and recovery point objective (RPO) are important factors to consider. RTO represents the time to recover, which might be two hours for one server and four hours for another server. RPO represents your potential data loss, which might be one business day of data with one server or two business days with another server. A high RTO environment is an environment in which you can recover server functionality quickly after an outage. A high RPO environment is an environment in which the data recovered is as up to date as possible.

? The frequency of your full server backups will vary according to the speed of your backup system and the amount of data you need to back up. The frequency at which you can create backups controls both the RPO and the RTO available to you. For example, with nightly backups, your RPO will be one business day, meaning that any server outage will likely result in the loss of an entire business day of data. Meanwhile, your RTO, indicating how long it actually takes to recover, will vary according to the amount of data you have to restore, the speed of your backup system, the load and available resources of the server on which you are performing a restore, and what I like to call the X factor-the X factor being any unforeseen issues you might encounter, such as a failure of the backup system itself or a tape in a set, and so forth.

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