RAID Array
How do you calculate overhead?
1/N (where N is the price of the second disk -meaning that that amount is used for duplicate information
What does the term JBOD mean?
Just a Bunch Of Disks or spanning the combination of disks in a single storage unit.
What are the benefits of striping? (RAID 0)
Provides an increase in performance.
What are some of the benefits in using RAID 5?
Provides an increase in read operations and fault tolerance
What are some of the benefits of Mirroring? (RAID 1)
Provides fault tolerance for a single disk failure.
What is a Mirrored Volume?
(RAID 1) Mirroring writes data to both drives in duplicate disks simultaneously. Does NOT increase speed. PROVIDES additional copy.
What is striping?
(RAID 0) The writing of information across two disks to speed up the writing. Fastest of the RAID arrays, but does not provide fault tolerance. OS sees the raid drives as one large drive
What is Duplexing?
Is similar to mirroring but includes multiple RAID controllers to mitigate fault points.
What is Operating System RAID?
RAID features within the OS. Life software RAID, but typically better as it is integrated into the system.
What does RAID Stand for?
Redundant Array of Independent Disks
What are the Requirements and Disadvantages of RAID 1
Requires minimal of 2 disks Most expensive, has 50% overhead (duplicate copy) Does not increase performance.
True or False, Hardware RAID is the most expensive method?
True, but provides much better performance.
In which type of RAID is the disk being identical most desired?
Hardware RAIDS
What is the advantage of RAID 5 over RAID 1?
Increased performance.
What is Striping with Distributed Parity? (RAID 5)
combines disk striping across multiple disks with parity(copy) for data redundancy. Parity information is stored on each disk. If a single disk fails, its data can be recovered using the parity information stored on the remaining disks
What is the disadvantage of JOBD?
No performance increase or fault tolerance.
What is the downside of a software RAID Array?
Not as reliable as hardware, uses CPU and relies on OSfor accessing info
How are RAID controllers with combined levels of RAID read?
0+1 (striped that is mirrored aka RAID 10), RAID 5+0 and RAID 5+1
What is true about memory for all RAID configurations?
Amount of disk pace used on each disk must be equal size
How do you create a RAID array with software?
Disk Management, Management, right click the drive and select the RAID option. Any RAID without on board RAID processor those classify as this.
How do you load a hardware RAID?
Enter CMOS set up, storage configuration-RAID, Restart/Keystroke (M for standard) during boot. Follow prompts from there.
How do we implement RAID?
Installing a RAID Array (Hardware)-Processes through RAID Installing software RAID Array (software)-uses part of the CPU for RAID
Is RAID a substitute for backups?
NO
Can you create RAID arrays on basic disks?
NO, they must be on a dynamic disk
What is the benefit of JBOD?
No overhead and disks/volumes can be different sizes.
What are the Requirements and Disadvantages of RAID 0
Requires minimal of 2 disks. Doesn't provide fault tolerance
What are the Requirements and Disadvantages of RAID 5
Requires minimal of 3 disks. Overhead of 33% with 3 disks, 25% with 4 disks, and 20% with 5 disks Write operations slower due to compute/write parity info.
Which type of Windows can create RAID arrays?
Windows 7 supports RAID 0 and 1 arrays in disk management. To preform RAID 5 you will need a hardware or software RAID.
