Storage Flashcards
1
Q
Main difference between EBS and Instance Store
A
EBS is persistent storage, Instance Store is deleted on stop of an instance
2
Q
What are EBS Volumes bound to?
A
A specific AZ
3
Q
How are EBS Volumes connected to EC2 Instances?
A
Through the Network
4
Q
What is an advantage that makes EBS Volumes flexible?
A
Since EBS Volumes are Network Drives. They can be dettached from an instance and attached to a different one
5
Q
What is a big limiation of EBS Volumes?
A
If it’s created in sa-east-1a, it can’t be attached to an EC2 instance in sa-east-1b. (Though you can snapshot a volume to move it)
6
Q
If you create a 30GB EBS Volume, what are you billed?
A
The 30GBs
7
Q
Can you extend the size of an EBS Volume?
A
Yes
8
Q
Which of these 2 are bound to a specific AZ: EC2 Instances or EBS Volumes?
A
BOTH
9
Q
What defines if an ebs volume is deleted when an instance is terminated?
A
If you enable the option “Delete on termination” for the ebs volume
10
Q
how is an instances ebs volume configured by default? And how are additional ebs volumes configured?
A
root ebs has “delete on termination” enabled by default, other ebs volumes have this option disabled by default.
11
Q
Where are Snapshots stored?
A
S3
11
Q
is there a way to move an EBS volume from one AZ to another AZ?
A
Yes. There is a way to migrate an EBS Volume to a different AZ. It’s with a snapshot. (Snapshots can be moved between AZs)
11
Q
What are snapshots in AWS?
A
A backup in s3
11
Q
How can we move an EBS Volume to a different AZ?
A
You can take a snapshot of a volume, then restore it to a new EBS Volume. With the option “Create Volume from snapshot”. Finally you can choose any az from the current region for the destination of the new volume.
11
Q
What does EBS Mean?
A
Elastic Block Store
11
Q
How can you make a snapshot storage cheaper?
A
Move it to an archive tier that is available for snapshots
11
Q
How cheaper is the cost of a snapshot moved to an archive tier?
A
75% cheaper
11
Q
What is the disadvantage of moving a snapshot backup to an archive storage tier?
A
It takes longer to restore. From 24 up to 72hs
11
Q
How can you protect EBS Snapshots from accidental deletion?
A
Set up the recycle bin for EBS Snapshots
12
Q
How long are deleted snapshots retained by the recycle bin?
A
Depends on the configuration. Minimum is 1 day, maximum is 1 year.
13
Q
What is FSR?
A
Fast Snapshot Restore: It gives you very lower latency to the i/o operations for the blocks when first accessed, on the first initialiation of a restored snapshot.
This option is enabled by snapshot
14
Q
What is FSR useful for?
A
When you need to restore a very big snapshot and you need extra performance so this process has to be done very quickly.
15
Q
Can we move an EBS Volume to a different region?
A
Yes. You can take a snapshot of it and then copy the snapshot to a different region. Finally restore the snapshot to a new volume in this new region.
16
Q
What is AMI?
A
Amazon Machine Image. Basically a EC2 Instance customization for deploying EC2 instances. Like a “Template”. But templates are a different thing in EC2 and aws.
17
What is the basic benefit of using AMIs?
Faster boot and configuration times because of the pre-packaged software you install in an AMI.
18
Are AMIs region specific?
Yes. You can copy them from one region to another.
19
What are the different kinds of AMIs?
Public AMIs: EC2 instance Images provided by AWS
Your Own AMIs: You make and mantain them
Marketplace AMIs: An AMI someone else made, and they may sell it.
20
Describe the AMI Creation Process:
AMI Creation Process:
Start EC2 Instance and customize it
Stop the instance (For data integrity)
Build an AMI (Building AMI creates EBS Snapshots behind the scenes)
21
What is the main disadvantage of EBS Storage?
It's network storage, so it has limited performance because of the added latency (Compared to a directly attached disk).
22
Why is Instance Store good? And how does this work?
It's a high performance storage. It's directly attached to the EC2 instance. This is because the instance store disk is in the same hardware that runs the instance.
23
Instance Store main advangate?
Better I/O Performance
24
Disadvantage of Instance Store?
It's ephemeral storage. If you stop/hibernate/terminate an instance its instance store is deleted.
25
Is instance store good as a long term storage?
NO. Its not persistent storage. Its ephemeral
26
What are good use cases for instance store? (And why)
Buffer, cache, scratch data, temporary content.
27
What is a big risk of using instance store? How do you prevent this?
If hardware fails there is risk of data loss. Prevent with Backup/replication solutions
28
What do the terms gp2 and gp3 mean? What is it best suited for?
It's a General Purpose EBS Volume. It means its a volume balanced for price and performance. Aimed for a wide variety of workloads. gp2/gp3 (SSD).
29
What does io1 and io2 mean?
Its provisioned IOPS volumes. The highest performance SSD in EBS storage. Made for low latency and high throughput workloads. It's for MISSION CRITICAL workloads.
30
What does st1 mean?
It's HDD. Bad compared to general purpose and block express SSDs. But it's low cost and its the high end for HDD EBS Storages. It's for frequently accessed workloads.
31
What does sc1 mean?
It's the lowest end disk type in EBS. It's HDD and designed for less frequently accessed workloads
32
Which type of EBS Volumes can be used as boot volumes?
Only General purpose gp2/gp3 SSDs, and provisioned iops: io1 and io2 block express SSDs.
33
How many types of EBS storage are there?
6: gp2, gp3, io2, io3, st1, sc1.
34
What are the use cases of general purpose EBS Volumes?
Good for Virtual Desktops, system boot volumes, and development or test environments.
35
What are the characteristics of general purpose EBS Volumes?
Cost effective
Low latency (For EBS)
Its SSD disk
Can boot from it
2 Types: gp2 and gp3
dont support multi-attach
36
Whats the difference between gp2 and gp3 storage types?
In gp2 you increase iops and bandwidth with the size of the disk.
In gp3 you can increase iops and MiB/s independently
37
What is Provisioned IOPS?
The fastest EBS storage type. io1 and io2. For critical applications
38
What are use cases of Provisioned IOPS?
Critical business applications that need sustained high IOPS performance. For example high performing Databases.
Any workloads that need great storage performance and consistently high disk performance.
(Io1 and Io2 are the only ones that support the Multi-attach function)
39
Which is faster, io1 or io2?
io2 Block Express
40
Whats the difference in speed between io1 and io2 storage types?
Io2 is faster.
Io1 provisions up to 32000 IOPS, and 64000 for Nitro EC2 instances.
Io2 Block Express provisions up to 256000 IOPS.
41
Which is faster, io1 or io2?
Io2
42
What are the types of EBS HDDs?
sc1 ad st1
43
Which is faster, sc1 or st1?
st1
44
What is the use case of st1?
For BIG DATA, Data Warehouses, log processing storages.
45
What is the difference between sc1 and st1?
ST1 is an HDD optimized for throughput. (500MiB/s - 500 IOPS)
SC1 is the slowest and lowest cost EBS storage. (250MiB/s - 250 IOPS)
46
What is the use case of sc1?
For data that is infrequently accessed. Because it's the slowest storage available. Its useful for when you need the lowest cost.
47
What are the characteristics of PIOPS EBS Volumes?
Fastest EBS Volumes
Can be used as boot volume
its ssd
its high IOPS
its the lowest latency in case of io2
Support Multi-Attach
48
what is function that EBS HDDs cant do?
They can't be used as boot volumes. Neither St1 nor Sc1
49
What is a key factor of using higher than 64000 IOPS or 16TiB disks on an EC2 instance?
You need Nitro System instances if you want that high of a performance or capacity.
50
What is Multi-Attach?
Lets you attach many instances to a single EBS Volume (This is for specific use cases)
51
What are limitations of Multi-Attach?
Up to 16 EC2 Instances can be attached to a single volume
Instances and EBS Volume must be within the same AZ
Only works with io1 and io2 volumes.
52
What are the Multi-Attach use cases?
Higher application availability in clustered apps.
Apps that must manage concurrent write operations
53
What are characteristics of Multi-Attach?
Each instance attached has full read & write permissions to the volume. (So they can read and write at the same time)
54
How many instances can be attached to the same ebs volume?
Up to 16 EC2 instances with multi attach
55
What does EBS Encryption encrypt?
Data at rest and in transit (between volume and instance) of EBS Volumes.
EBS Volumes, Snapshots, Volumes created from snapshot, are all encrypted
56
Who handles EBS encryption?
AWS Behind the scenes.
57
How much does EBS Encryption impact latency?
Barely. Latency impact is minimal
58
What kind of encryption is used for EBS?
AES-256 encryption, using a KMS.
59
Describe the steps for encrypting an unencrypted EBS Volume
1 Snapshot of volume
2 Encrypt the snapshot
3 Create new EBS Volume from the snapshot
4 Attach new volume to the original instance
60
Which protocol does EFS use?
NFS (Version 4.1)
61
What function differentiates EFS from ebs?
It can be attached to instances in different AZs.
62
What are the main characteristics of EFS?
Highly available
Scalable in size
Very expensive, 3 times that of a gp2 EBS Storage.
You pay what you use
63
How does EFS Scale in storage size? And how much storage do you pay for?
EFS Scales automatically. The space occupied is the size of the EFS System. It can grow or shrink depending on use, and the space occupied is what you pay for
64
Use cases of EFS are:
Web servers, wordpress sites, content management and data sharing.
65
Which OS is EFS compatible and incompatible with?
It's compatible with Linux but incompatible with Windows.
66
Does EFS support Encryption? How does it work?
Yes. With a KMS Server.
67
How do you do capacity planning with EFS?
You don't. You pay per use. And it scales automatically.
68
What are the two modes of EFS?
Performance and Throughput
69
Which options do you have for EFS File systems regarding zones?
You can choose to store an EFS File system in a region, or in a single AZ, which is cheaper.
70
How can you most simply back up an EFS File System?
Enabling automatic backups in the EFS File system creation, or later.
71
How do save costs of the stored data in an EFS File System? How does this work?
With lifecycle management. You transition files to a different tier based on how often these files are accessed.
72
What is lifecycle management in EFS?
A way to reduce costs of EFS storage by moving files between tiers of storage, less used files are moved to cheaper tiers.
73
What are the tiers of EFS storage and what are the differences?
Standard tier: Most frequently accessed files and the default tier.
IA: Less frequent access. Cheaper, but there is a cost every time a file is accessed.
Archive: even cheaper. For Rarely accessed data. Charged more per gb read than ia
74
What is a caveat of the IA storage class?
Its cheaper than the standard but there is a fixed cost each time you access a file in this tier. (But since these are less frequently accessed, it's overall cheaper than the standard tier)
75
How does lifecycle management move file between tiers in EFS?
You set how many days have to go by before moving a file from standard to IA, and to archive. You also set if a file is moved back to standard tier or not after it being accessed once.
76
Are EFS files that get moved to IA or archive tiers stored there forever?
Yes, unless you set to move back to standard after a file is accessed once. You can set to move back to standard after access, or to just keep it in the current tier after access.
77
What are the 2 EFS Performance modes? What are the differences between them? What are some use cases?
General purpose and MAX I/O.
General purpose is lower latency. (For web servers, shared files)
MAX I/O is higher throughput and IO, but higher latency too. (For media transfers, big data)
78
How much can EFS scale?
To Petabyte scale, more than 10G/s throughput, and thousands of concurrent NFS clients.
79
Which EFS file system Throughput mode scales with the EFS storage size?
Bursting mode.
80
Which EFS Throughput mode is more flexible?
Enhanced Elastic
81
Which EFS Throughput mode has 2 options, what are they and what is the difference between them?
Enhanced mode. It has elastic or provisioned.
Elastic means your throughput scales auto with how much workload activity there is against the EFS file system.
Provisioned is a set value you choose for the throughput. You get a burst of x3 that set value.
82
What happens with performance mode when you choose elastic throughput?
You can't set the performance mode to Max I/O when using elastic throughput.
83
What is bursting, elastic and provisioned in EFS? What are each of them?
The 3 main modes for throughput. Bursting scales with storage size.
Elastic scales automatically with use, and provisioned is a static preset value.
84
Inside which service do you create security groups?
EC2
85
Which network configurations do you need to do to create an EFS File System?
You need to choose a VPC, and then a subnet and IP address for the File System per Availability Zone. You also need a security group to control who can access the NFS shares.
86
what is the procedure to attach an EFS to an EC2 instance automatically?
When you create an EC2 instance, you can select an existing or create a new EFS File system, and check a box to automatically create security groups between it and the instance, and also check another box to automatically add user data to mount this file system to the instance.
(You need to specify a subnet and therefore an AZ before doing this).
87
What is the procedure to attach an EFS to an EC2 instance manually?
To attach an instance to an EFS system, first, you need to have network connectivity from the instance to the EFS system in the NFS protocol. Through security groups and security rules, applied to the Ip addresses of the instance and EFS, or alternatively, applied directly to an opposite security group belonging to the instance and EFS system.
Then you need to mount a share of the EFS through the command line or an UI utility of the linux system.
88
Can you boot an OS from EFS?
No you can't.
89
How do you control access to your EFS?
With security groups
90
What are the security groups attached to in EFS?
To the mount points of the EFS File system. (Mount points equate to an ENI).
91
Which of these file systems can be attached to multiple EC2 instances? EBS or EFS?
Both. EFS easily because its an NFS. EBS only through multi attach which is only supported for io1 an io2 types.
EBS multiattach is limited to 16 instances, while EFS can mount to 100s of instances in different AZs.
92
What is a limitation of EBS against EFS?
EBS volumes are locked to a single AZ. EFS can connect to multiple AZs through use of multiple ENIs a region. One for each AZ to which the instances can connect to.
93
What is a possible issue of backing up an EBS Volume?
It consumes IO and can slow the volume for the instance. You should do it when it's not being used.
94
What are the disadvantages of EFS?
Can't boot from it
Only works with linux
95
Which is cheaper, EFS or EBS?
EBS
96
How can you apply cost savings in EFS?
With lifecycle management you can use storage tiers.
97
What is an EFS Mount Target?
An ENI in a VPC and subnet with an ip address and a dns name where you can mount the EFS share to your instance.
If the EFS is regional, you'll have a mount target per AZ.
In the mount target you configre security to and from the EFS File System.
98
Can I use an AMI in an european region to create an instance in another european region?
NO. AMIs are region specific.
99
Why would you copy an AMI to another region?
To be able to launch instances from this AMI in a different region
100
Which type of storage offers the highest IOPS of all the options available?
Instance Store.
101
How can you make an instance store volume be persistent?
With backup/replication methods.
For example, you can replicate an instance to a different az. If your original instance is stopped for any reason and the instance store is lost. You have a replica ready to take its place. You will lose data depending of the RPO set for the replica, and depending of the tool you use for this hypothetical replica.
102
103
What is block express?
It's io2 volumes attached to EC2 nitro instances. These become block express volumes. Block express can deliver higher throughput and IOPS, higher storage capacity, and sub millisecond latency.
Up to 256000 IOPS 4000MB/s
