EC2 - RAID, Volumes & Snapshots

Question 1

What does RAID stand for?

Answer 1

Redundant Array of Independent Disks (putting together a bunch of disks as one disk)

Question 2

RAID types

Answer 2

RAID 0, RAID 1, RAID 5, RAID 10

Question 3

RAID 0

Answer 3

Striped, No Redundancy (if one disk fails, the entire volume fails), Good Performance (use: gaming)

Question 4

RAID 1

Answer 4

Mirrored (take one disk, mirror a copy to another disk), Redundancy

Question 5

RAID 5

Answer 5

at least 3 disks, good for reads, bad for writes, AWS does not recommend ever putting RAID 5’s on EBS

Question 6

RAID 10

Answer 6

Striped & Mirrored, good redundancy, good performance

Question 7

Where are RAID volumes used on AWS?

Answer 7

If you do not get disk I/O you require, add multiple volumes and create RAID array (usually RAID 0 or RAID 10 on AWS)

Question 8

Best practice when launching Windows instances

Answer 8

Create a new keypair for Windows instances, separate from Linux instances

Question 9

Username, password for Windows instances

Answer 9

User = Administrator
Password = upload private key file into "Retrieve Password" window to obtain password

Question 10

To manage disks…

Answer 10

Right-click, Disk Management. Right-click on an unallocated volume and choose volume type you want to create, select drive you want the RAID volume assigned to

Question 11

How can I take a Snapshot of a RAID array - background?

Answer 11

Problem - Take a snapshot, the snapshot excludes data held in the cache by apps and the OS. This tends not to matter on a single volume; however, using multiple volumes in a RAID array, this can be a problem due to interdependencies of the array.

Solution - Take an application consistent snapshot

Question 12

How can I take a Snapshot of a RAID array - continued

Answer 12

Stop the application from writing to disk. Flush all caches to the disk.

How can we do this? Freeze the file system, unmount the RAID array, shut down the associated EC2 instance (easiest)