Monitoring and Metrics Flashcards
Largest EBS size
16TiB
How many instances can an EBS volume be mounted to at any time?
1
What format does EBS use?
Raw, unformatted. Must be managed by OS
True or false: UBS supports RAID
True, as long as the OS supports RAID
True or False: EBS volume and the instance must be in the same availability zone?
True.
By default, what happens to the EBS volume when the instance is terminated?
The volume will persist.
By default, what happens to root volumes when the instance is deleted?
The root volume is deleted. Modify the DeleteOnTermination to change this.
In order to ensure root volumes are not deleted when the instance is deleted, what must be done?
uncheck, or unflag the DeleteOnTermination option
Where are EBS snapshots stored?
S3
True or false: Snapshots are an exact copy of the EBS volume?
True: If the volume is encrypted, the snapshot and the restore will be encrypted.
True or false: Each snapshot is a full copy of the EBS volume?
False: Snapshots are incremental. Only the changes since the last snapshot will be copied.
True or false: Multiple EBS volumes can be mounted to a single instance?
True: While any one volume can only be attached to one instance at a time, multiple volumes can be attached to an instance.
SSD - IOPS standard size
256kb I/O size
SSD - One 1024kb operation will equal how many IOPS?
4
SSD - Four 64kb sequential operations will equal how many IOPS?
1
SSD - Four 64kb random operations will equal how many IOPS?
- Random operations cannot be grouped together and will each be counted as an IOPS.
What is a burst bucket?
Allows an EBS volume to “burst” above its basic performance.
How are bursts allocated?
Through burst credits
How are burst credits earned?
Volumes earn burst credits over time and depend on volume type
True or false: Volumes can earn unlimited credits?
False: They are limited.
Under what metric is the burst credits reported in CloudWatch?
BurstBalance metric
What is the minimum gp2 SSD volume size?
1GiB
What is the maximum gp2 SSD volume size?
16TiB
What is the minimum gp2 IOPS
100 IOPS
What are the two SSD volume types?
GP2 - General Purpose
io1 - Provisioned IOPS
What is the maximum gp2 IOPS
10,000 IOPS
How is the maximum IOPS for gp2 volumes determined?
3 IOPS per 1 GiB of volume size
ex. 100GiB volume = 300 IOPS
What is the maximum throughput of gp2 volumes?
160MB/s
How many IOPS for a gp2 volume size of 20GiB?
100 IOPS. Remember, while the formula is 3 IOPS per GiB of volume, the minimum IOPS is 100.
What is the starting gp2 burst bucket credit balance?
5.4 million. This provides 3000 IOPS for 30 minutes
How are gp2 burst credits earned?
3 IOPS per GiB of volume size
What is the minimum io1 volume size?
4GiB
What is the maximum io1 volume size?
16TiB
What is the minimum IOPS for io1?
100
What is the maximum IOPS for io1?
32,000
How are IOPS determined in io1 volumes?
io1 IOPS is assigned by the user from 100 to 32,000
How is the maximum IOPS for io1 volumes determined?
50 IOPS per GiB
What is the smallest volume size required to achieve 32,000 IOPS in io1 volumes?
640
640 x 50 = 32,000
What is the AWS recommended IOPS to GiB ratio?
> 2:1
What is the maximum throughput of io1 volumes?
500MB/s
What are the HDD volume types?
Throughput optimized (st1) Cold HDD (sc1) Magnetic
Is st1 supported as boot device?
No
Is sc1 supported as a boot device?
No
What is the st1 volume type?
Throughput optimized
What is the code for throughput optimized volumes?
st1
Can you use magnetic storage as a boot device?
Yes
What workloads are sc1 volumes ideal for?
infrequently accessed data. Low storage cost
What is the max throughput of sc1 volumes?
250MB/s
What workloads are st1 volumes ideal for?
frequently accessed and throughput intensive workloads
What is the minimum st1 volume size?
500GB
What is the maximum st1 volume size?
16TiB
What is the ideal use case for magnetic volumes?
Where cost is a primary factor.
What is the smallest volume size for magnetic volumes?
1GiB
What is the largest volume size for magnetic volumes?
1TiB
For st1 volumes, what is the ratio for throughput baseline?
40MB/s per TiB
Max throughput: 500MB/s
For sc1 volumes, what is the ratio for throughput baseline?
12MB/s per TiB
Max throughput: 250MB/s