Class 10 | Backup and Recovery | CRM Notes

Introduction to backup
“Backup” refers to the process of copying and archiving data so that it can be used to restore the original after a data loss event. Restoring data that has been lost, mistakenly deleted, corrupted, or rendered inaccessible is the process of data recovery.

Backup methods, device and media

Full Backup:
 A full backup involves making a complete copy of all selected data. It provides the most comprehensive backup but requires the most storage space and time to complete. This type of backup has the benefit of making it simple and quick to restore your data. The drawbacks is that making full backups can take a while and calls for the user to have a big backup window.

Incremental Backup:
Incremental backups only copy the data that has changed since the last backup, whether it was a full backup or an incremental backup. This saves storage space and time but requires multiple backups to fully restore data.

Differential Backup:
Differential backups copy all changes made since the last full backup. Unlike incremental backups, they do not require multiple backups to fully restore data, but they do consume more storage space compared to incremental backups over time.

Types of storage devices:
The storage device used to hold a backup is just as important as the device itself, so the most recent storage options are described below:

External Hard Disk Drive (HDD):
 External HDDs provide large storage capacities at relatively low costs. They use spinning magnetic disks to store data. They are suitable for backing up large amounts of data and for transferring files between computers.

Solid-State Drive (SSD):
 SSDs use flash memory to store data, offering faster read/write speeds compared to HDDs. They are more resistant to physical shock and consume less power, making them suitable for portable devices. While typically more expensive per gigabyte than HDDs, they offer faster performance, making them ideal for tasks requiring speed, such as running operating systems or frequently accessed data.

USB Flash Drive:
USB flash drives, also known as thumb drives or USB sticks, are small, portable storage devices. They use flash memory for storage and connect to computers via USB ports. Flash drives are convenient for transferring small amounts of data between devices or for carrying files on the go.

CD (Compact Disc) Technology:
CDs are optical storage devices that use lasers to read and write data onto a reflective surface. They offer relatively low storage capacities compared to other storage media. CDs are commonly used for distributing software, music, and other multimedia content.

DVD (Digital Versatile Disc) Technology:
 DVDs are similar to CDs but offer higher storage capacities. They are commonly used for storing large amounts of data, such as movies, software, and backups. DVDs come in different formats, including DVD-R, DVD+R, DVD-RW, and DVD+RW, with varying levels of compatibility and rewritability.

Online Storage (Cloud Storage):
 Online storage involves storing data on remote servers accessed via the internet. It offers the advantage of accessibility from anywhere with an internet connection and provides off-site backup for data protection. Popular online storage services include Dropbox, Google Drive, Microsoft OneDrive, and iCloud.

Backup scheduling and media rotation system
Backup scheduling and media rotation systems are essential components of a robust backup strategy, ensuring data protection and recovery readiness. Here’s an overview of each:

Backup Scheduling:
 Determine how often backups need to occur based on factors like the rate of data change, business needs, and available resources. Common frequencies include daily, weekly, or even in real-time for critical systems. Schedule backups during off-peak hours to minimize disruption to regular operations. Consider factors like system usage patterns and network traffic.  Define how long backup data should be retained. This could vary based on regulatory requirements, business needs, and available storage space. For example, you might retain daily backups for a week, weekly backups for a month, and monthly backups for a year. Allocate a specific time frame for backups to complete within, ensuring they don’t overlap with other critical processes and maintenance tasks. Assign priorities to different types of data and systems based on their criticality to the organization. Ensure that the most critical data is backed up more frequently and with higher priority.

Media Rotation System:
 Decide on the types of backup media to use, such as tapes, disks, or cloud storage. Each type has its advantages and considerations regarding cost, durability, and accessibility. Implement a rotation schedule to cycle through multiple backup media. This helps distribute wear and tear, mitigate the risk of media failures, and ensure redundancy. Grandfather-Father-Son (GFS) is popular backup media, This involves rotating between daily (sons), weekly (fathers), and monthly (grandfathers) backups. A more complex rotation scheme that involves rotating backup sets of different ages. Develop a rotation pattern tailored to your organization’s specific needs, considering factors like data volume, retention requirements, and backup frequency. Store backup media off-site to protect against disasters like fires, floods, or theft. Rotate media between on-site and off-site storage locations according to the rotation schedule. Regularly verify backup media integrity and conduct test restores to ensure data recoverability. This helps identify and address any issues before they become critical during a data loss event.

Introduction to RAID
RAID, which stands for Redundant Array of Independent Disks, is a technology used to combine multiple physical disk drives into a single logical unit for the purposes of data storage, performance improvement, or both. RAID systems offer increased data reliability, fault tolerance, and/or performance enhancements compared to single disk configurations.

RAID Levels:
There are several RAID levels, each offering different combinations of redundancy, performance, and capacity. Some common RAID levels include:
RAID 0 or striping:

Provides striping without redundancy. This can improve performance by spreading data across multiple disks but offers no fault tolerance.
a) High performance.
b) There is zero capacity loss in RAID 0.
c) Zero fault tolerance.
d) write and read will be good performance.

RAID 1:
Involves mirroring, where data is duplicated across multiple disks. This provides redundancy but does not necessarily improve performance.

RAID 5:
Uses striping with distributed parity. Data and parity information are distributed across all disks in the array. RAID 5 offers a balance of performance and fault tolerance.

RAID 6:
 Similar to RAID 5 but with additional parity information for increased fault tolerance. RAID 6 can withstand the failure of two disks simultaneously.

RAID 10 (or RAID 1+0):
Combines mirroring and striping. Data is mirrored across multiple disk pairs, and then striping is applied across these mirrored pairs. RAID 10 offers both high performance and fault tolerance but requires a larger number of disks.

Different Types of Data Recovery Systems
Organizations and enterprises employ a variety of various types of data recovery systems to recover lost data. To decide a policy and recovery system that will be suitable for your firm, you must first evaluate all of the important levels of your data and systems. Only then can you choose the type of data recovery system that is appropriate for your business. There are various different forms of recovery you can apply in the event of data loss, presuming you have completed the data assessments.

Bare Metal Recovery:
Backing up the complete system, including the operating system, software programs, and data, is required for bare metal recovery. In the event of data loss, bare metal recovery enables you to recover the complete operating system in a single step, cutting down on the recovery process’ hours-long duration. By reinstalling the operating system, software programs, and restoring the data and settings, you can avoid having to reformat everything from start.

Online Disk Backup:
Data that changes regularly each day can be backed up more frequently un online disk backup, which is perfect. An online disk backup service also offen tiered recovery architecture, which offers enterprises that need frequent backups of important data greater flexibility and options, as well as sporadic backups of less important data.

Continuous Data Protection:
Continuous data protection (CDP), often known as continuous backup, reduces recovery time by using a form of data backup that serves two purposes Continuous data protection allows you to backup data to both an offsite location and your local area network at the same time. The CDP can access the offsite data backup system if the organization experiences onsite data loss.
A continuous data protection backup also maintains a log of any data modifications that have taken place since the previous backup in addition to using two different methods of data backup. A continuous data protection system can be easily installed, and if it has disk storage, recovery time is minimal.

 

 

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