Prev Question
Next Question

Out of the stripping options available for the EBS volumes, which one has the following
disadvantage :
‘Doubles the amount of I/O required from the instance to EBS compared to RAID 0, because
you’re mirroring all writes to a pair of volumes, limiting how much you can stripe.’ ?

A.
Raid 0

B.
RAID 1+0 (RAID 10)

C.
Raid 1

D.
Raid

Explanation:
http://docs.aws.amazon.com/AWSEC2/latest/WindowsGuide/raid-config.html
raid 0 and 1 are the common types. Raid 5 and 6 are not recommended because of the
extended stripe. If you encounter this question on the exam I suspect the answer options will
be different.
Raid 1 Disadvantage
Does not provide a write performance improvement; requires more Amazon EC2 to Amazon
EBS bandwidth than non-RAID configurations because the data is written to multiple volumes
simultaneously.
Raid 0 Disadvantage
Performance of the stripe is limited to the worst performing volume in the set. Loss of a single
volume results in a complete data loss for the array.
Raid 5 and 6 notes
RAID 5 and RAID 6 are not recommended for Amazon EBS because the parity write
operations of these RAID modes consume some of the IOPS available to your volumes.
Depending on the configuration of your RAID array, these RAID modes provide 20-30% fewer
usable IOPS than a RAID 0 configuration. Increased cost is a factor with these RAID modes
as well; when using identical volume sizes and speeds, a 2-volume RAID 0 array can

outperform a 4-volume RAID 6 array that costs twice as much.

Prev Question
Next Question

Leave a Reply

Your email address will not be published. Required fields are marked *