Chapter 9 - Data Protection Flashcards
What is the difference between data and information?
The difference between data and information is that data is raw facts, information is things inferred or learned from distilling data.
How can data be protected while it is being transmitted? How can data be protected while it is being processed?
Data can be protected while it is being transmitted through a secure cryptographic system. Data can be protected while being processed via hardened hosts and securely coded applications.
What are some ways that data can be lost?
Data can be lost by a number of ways, either through mechanical hard drive failure, fires and floods, malware, or just theft or misplacement.
How does backup ensure availability?
Backup ensures availability, in that even in the event of a disaster, the backup will be available.
Distinguish between file/directory data backup and image backup.
A file/directory data backup just backs up selected files or file/folder structures. An image backup backs up everything, including registry settings, programs, personalization, and so forth. An image allows a computer to be “rebuilt”.
Why is file/directory backup attractive compared with image backup?
File/directory backups are attractive compared to image backups because image backups are known to be very slow, which prevents frequent backups.
Why is image backup attractive compared with file/directory data backup?
Image backup is attractive compared to file/directory backups because everything is backed up, from files and directories to personal settings and registry.
What is shadowing? What are the advantages of shadowing over file/directory data backup?
Shadowing is a method of backup where a backup copy of each file being worked on is written every few minutes to the hard drive or to another location.
The advantage of shadowing over file/directory data backup is that the time frame between backups is minimal, so very little is lost.
How is shadowing limited?
Shadow backups are limited by storage space, so older files are allowed to “roll off”.
Why don’t most companies do a full backup every night?
Most companies don’t do a full backup every night due to the time it takes to perform a full backup.
What is incremental backup?
Incremental backup is when only the data that has been changed since the most recent backup is saved.
What are the advantages of centralized backup compared to local backup?
Centralized backup has several advantages over local backup; centralized backup only requires one or two computers, so it is economical. Also, since the backups are localized, it is far easier to determine if backup policies are being followed.
What is CDP, and why is it attractive? Why is it expensive?
CDP, also known as continuous data protection, is when multiple sites back up one another on an ongoing basis, so if one fails, the others immediately take up the slack. It is attractive because there is very little loss of data, but is expensive because it requires a very high speed data transmission link between sites.
Why is backup over the internet to a backup storage provider attractive for client PC users? What security risks does it create?
Internet backup services are attractive to PC client users because it is highly convenient. Unfortunately, backups are slow, and there’s the chance that the company holding the data might lose control of it.
What is a mesh backup? Why is it desirable?
A mesh backup is when the client computers on a network back up one another. It is desirable as it makes client PC backups automatic.
Why is magnetic tape desirable as a backup medium? Why is it not?
Magnetic tape is desirable because it can store the largest amount of data at the lowest cost per bit. Unfortunately, it’s also agonizingly slow.
Why is backup onto another hard drive attractive? Why is it not a complete backup solution? How can this limitation be addressed?
Backup onto another internal hard drive is attractive due to the high speed, but it suffers from the limitations of time decay, and the threat of damage to the PC or theft. This can be addressed by using a two-layered approach, such as also backing up to a DVD.
How much data can be stored on a dual-layer DVD?
A dual-layer DVD can store about 8 GB of data.
What is the advantage of burning backup data onto optical disks?
The advantage of storing backup data on optical disks is that almost all PCs have optical disk burners (although not as much anymore).
Is storing backups on optical disks for several years likely to be safe?
No, it is not likely to be safe to store backups on optical disks for several years. They may start to degrade after 2.
How can disk arrays ensure data reliability and availability?
Disk arrays can ensure data reliability and availability because it stores redundant data on several disks, so that if one drive fails, the others can still function.
Explain RAID 0.
RAID 0 is a form of disk array by allowing simultaneous writing to multiple disks at once, known as striping. These disks have no redundancy, however, so if one fails, they all become worthless. This provides no additional reliability.
Explain RAID 1
RAID 1 is a form of disk array backup that uses a second disk as a “mirror”, an exact copy of the first disk. It gives a good degree of reliability, in that if one disk fails, it can be swapped out for another almost effortlessly.
Explain RAID 5.
RAID 5 is a form of disk array backup that uses striping across multiple disks to increase transfer speeds, but also includes what’s called parity bits, which allow for the recovery of any ONE disk should it be destroyed.
What are the advantages of RAID 5 over RAID 1?
RAID 5 offers a degree of reliability with the parity bits, as well as striping, which increases read-write speed. RAID 1 can only offer reliability.
Which RAID level has the fastest read-write speeds?
RAID 0 has the fastest read-write speeds.
Is RAID 5 appropriate for home users? Why or why not?
RAID 5 is likely overkill for home users, as most home users won’t have more than two disks to put in RAID.
What should backup creation policies specify?
Backup creation policies should specify what data should be backed up, how frequently it should be backed up, and how frequently restorations should be tested.
Why are restoration tests needed?
Restoration tests are needed to ensure that restores work.
Where should backup media be stored for the long term?
Backup media should be stored at another site by default.
What should be done about backup media until they are moved.
Until backup media can be moved off-site, it should be stored in a fireproof and waterproof safe.
Why is the encryption of backup media critical?
The encryption of backup media is critical because said material can be stolen in-transit to off-site storage.