.01 - .14 Data storage resiliency and disaster recovery methods Flashcards
Which of the following is the most cost-effective strategy for backing up enormous quantities of data when a system needs to be available seven days a week?
Implementing a duplicate storage area network (SAN) and replicating the data to a second SAN
Deploying storage infrastructure at a hot site
Making a full backup weekly and an incremental backup every night
Implementing a fault-tolerant disk-to-disk backup solution
Implementing a fault-tolerant disk-to-disk backup solution
Fault tolerance is the ability of a system to suffer a fault but continue to operate. Fault tolerance permits the backup of data to be performed without impacting system performance and allows enormous data to be backed up in a short backup window. In case of a failure, the fault-tolerant system can fail over immediately to the other disk set.
Making a full backup weekly and an incremental backup every night
This method would not enable the system to be available seven days a week. The only feasible way for a system to remain online is to duplicate the data to a server backed up to tape or implement a disk-to-disk solution that is effectively the same thing.
Implementing a duplicate storage area network (SAN) and replicating the data to a second SAN
This method provides redundancy and data protection but not a backup solution. There is a risk that a fire or flood at the site could lead to data loss since the two systems are at the same site.
Deploying storage infrastructure at a hot site
This method provides a great deal of redundancy and availability to enable the system to stay operational; it does not address the need for long-term data storage. In addition, this is not an efficient method of backing up data.
Reference: 7113.02
There are security mechanisms for limiting and controlling access to and use of computer system resources such as fault-tolerant techniques (e.g., disk mirroring and RAID technology) and redundancy techniques (duplicate equipment) against data loss and denial of service.
Fault tolerance is the ability of a system to suffer a fault but continue to operate.
Redundant array of inexpensive or independent disks (RAID) technology uses several disks in a single logical subsystem. To protect data against a single point of failure and to reduce or eliminate downtime from disk failure, database servers may employ disk shadowing or data mirroring. The main purpose of RAID is to provide backup so if one disk fails, all the data is immediately available. Fault tolerance is achieved by adding redundant components such as additional disks within a RAID array or additional servers within a failover clustered configuration.
RAID provides performance enhancement and fault-tolerant capabilities through hardware or software solutions, breaking up data and writing data to a series of multiple disks concurrently to improve performance.
Fault-tolerant hardware increases system resilience. Fault management is the detection, reporting, diagnosis, correction, and prevention of faults and fault conditions. A fault is a malfunction or abnormal pattern of behavior that is causing or will cause an outage, error, or degradation of communications services.
Relevant Terms
Backup
Reference
7113.01
7113.02