CompTIA Network+ Certification (N10-003) Part 16

Mirroring requires a minimum of two disks. Striping and parity across all disks requires a minimum of three disks.

RAID-0 is not a fault tolerance system. It uses striping on all disks to improve performance but does not use parity to provide fault tolerance.

Cold sites rely on back ups for data recovery. This implementation has no fault tolerance and, hence, no expense, except for back up equipment.

All files are backed up during a full backup.

RAID-1 is a disk fault tolerance system in which two disks are exact mirrors of each other. Should the one disk fail, the system would still be operable, the failed disk can be replaced, and the mirror rebuilt. However, this does not improve performance.

RAID-6 is similar to RAID-5. It implements striping with two independent sets of parity across all disks. This allows for the recovery from up to two simultaneous disk failures and requires an additional disk over RAID-5.

An incremental backup includes all the files that have changed since the last full backup. To keep track of the files that have changed the Operating System uses the archive bit. Whenever a file is altered the archive bit is set.

RAID-5 uses striping and parity across all drives to provide fault tolerance.

RAID-0 is not a fault tolerance system. It uses striping on all disks to improve performance but does not use parity and thus does not provide fault tolerance.

Surge protectors provide only a limited amount of protection. A surge protector controls the amount of voltage, current (amps), and noise that can get through to your computer. They are designed to protect the computer against large spikes and surges. Small increases in voltage, which may not cause immediate damage but can damage sensitive computer equipment over time, are allowed to pass. They also do not provide protection against power outages.

RAID-1 is a disk fault tolerance system in which two disks are exact mirrors of each other. Should the one disk fail, the system would still be operable, the failed disk can be replaced, and the mirror rebuilt.

An incremental backup includes all the files that have changed since the last backup.

Disk striping breaks up the data into small portions and sequentially writes the portions to all disks simultaneously in small areas called stripes. These stripes maximize performance because all of the read/write heads are working constantly. This requires a minimum of three disks.

Cold sites rely on back ups for data recovery. This implementation has no fault tolerance and, hence, no expense, except for back up equipment.

The archive bit is not cleared during a Differential backup. These files will be backed up again during subsequent Incremental or Differential backups.

Disk striping is the process of writing bits of data across multiple disks.

RAID-6 is similar to RAID-5. It implements striping with two independent sets of parity across all disks. This allows for the recovery from two simultaneous disk failures and requires an additional disk over RAID-5. RAID-5 requires a minimum of three disks and RAID-6 requires four.

All files are backed up during a normal backup, regardless of the archive bit. A normal backup is also referred to as a full backup.

Warm sites are not as expensive as hot sites because it requires redundant copies on critical network components, such as servers, rather than redundant copies of all computer systems.

RAID-5 uses parity information to reconstruct missing data should a disk fail. Parity provides fault tolerance.

Incremental backups only back up the files that have changed since last backup. Incremental backup is the quickest backup method. Therefore we need to restore the last full backup then the incremental backups in sequence.

RAID-5 uses striping and parity across all disks to provide fault tolerance and requires a minimum of three disks.

Differential backups only back up the files that have changed since last full backup whether those files have been backed up in the previous differential backup or not as the differential backup does not reset the archive bit on the files. Therefore we need only restore the last full backup followed by the last differential backup.

A differential backup includes all the files that have changed since the last full backup.

RAID 10 is a combination of RAID-1 and RAID-0. It implements striping in an array of two disks, and then mirroring across two arrays. This requires a minimum of four disks (two disks per array).

RAID-3 uses striping and parity on a dedicated drive to provide fault tolerance.

Line conditioners provide the highest level of power protection for electronic devices.

Both the Full backup and Incremental backup clears the archive bit of the files that have been backed up. These files will not be backed up in subsequent Incremental or Differential backups.

A surge protector is designed to protect electrical equipment from surges and spikes but cannot protect against power outages as it does not have its own power supply.

Disk mirroring and disk duplexing are fault tolerant solutions that require a minimum of two disks. Disk mirroring requires only one controller while disk duplexing requires two controllers.