EBS Flashcards
This deck aims to help retain concepts related to the AWS EBS service.
What is direct (local) storage for an EC2 instance?
Instance store (storage that is directly connected to the EC2 host)
What file-level computer data storage server is connected to a computer network providing data access to a heterogeneous group of clients?
Network Attached Storage (NAS)
What are the main considerations when choosing between an instance store and an EBS volume for an EC2 instance?
EBS:
- Persistence (to avoid data loss)
- Resilience (to avoid hardware failure)
- Instance lifecycle isolation
Instance Store:
- Best performance
- Included in the price (makes sense to utilize them)
What are the main considerations to keep in mind when using an EC2 instance store?
- Temporary (data can be lost, ephemeral0, ephemeral1, …)
- Highest storage performance
- Included in the instance price
- Attached at launch only
Is the EC2 Instance Store a persistent storage solution?
No, the EC2 instance store is temporary (ephemeral) storage (EBS volumes are used as a persistent storage solution)
What type of storage is represented as a file share, a ready-made file system with a structure, mountable, but not bootable?
File Storage
- EFS using NFS protocol
- FSx for Windows File Server using SMB protocol
What computer network provides consolidated, block-level data storage access?
Storage Area Network (SAN)
What type of storage is represented as a collection of addressable blocks, with no structure, mountable, bootable, with the file system created on top by the OS?
Block Storage (e.g. EBS using iSCSI protocol)
What is the preferred number of bytes the file system uses to read and write files?
IO Block (commonly 4096 bytes)
What abstract system enables customers to store their data in its native format, thus any type of data can be stored in it, has a flat structure, is not mountable, and is not bootable?
Object Storage (e.g. S3 using HTTPS protocol)
What measures the number of read and write operations a storage device can perform in one second?
Input/Output Operations Per Second (IOPS)
What scalable and high-performance storage service is designed to provide block storage capability for EC2 instances?
Elastic Block Storage (EBS)
What measures the amount of data transferred to and from the storage device per second?
Throughput (IO block * IOPS = throughput)
Can EBS volumes be encrypted?
Yes, using the KMS service
What is the resiliency posture of the EBS service?
EBS is an Availability Zone-resilient service
Once the EC2 instance is terminated, is the EBS volume also deleted?
No, EBS volumes are persistent and not linked to the instance lifecycle
How do you create a copy of an EBS volume in another region?
- Create EBS volume snapshots (snapshots are stored in S3, region-resilient service)
- Copy EBS volume snapshots to another region
- Use EBS volume snapshot to create an EBS volume
Can an EC2 instance format an EBS volume with a file system?
Yes, once mounted, the EC2 instance OS can format the EBS volume with a file system such as Ext4 for Linux instances or NTFS for Windows instances
What EBS volume types are there?
- SSD General Purpose (gp2, gp3)
- SSD Provisioned IOPS (io1, io2)
- HDD (st1, sc1)
Name the EBS volume type considering the following characteristics:
Durability: 99.8% - 99.9%
Volume Size: 1 GiB - 16 TiB
Max IOPS: 16,000 (16 KiB I/O)
Max Throughput: 250 MiB/s
Ratio: 3 IOPS per GB
gp2 (General Purpose)
What are the main considerations to take into account when choosing the gp2 EBS volume type?
Implements IO credit allocation system:
- 100 IO credits per second refill (100 IOPS)
- Beyond 100 IO fill rate, 3 IO/sec per GB of volume size
- Burst up to 3,000 IOPS by depleting the credits
Ensure that credits are being refilled and not depleted
Name the EBS volume type considering the following characteristics:
Durability: 99.8% - 99.9%
Volume Size: 1 GiB - 16 TiB
Max IOPS: 16,000 (64 KiB I/O)
Max Throughput: 1,000 MiB/s
Ratio: 500 IOPS per GB
gp3 (General Purpose)
What are the main considerations to take into account when choosing the gp3 EBS volume type?
- Standard 3,000 IOPS and 125 MiB/s throughput
- 20% cheaper than gp2, with additional costs for higher IOPS and throughput
What are the use cases for the General Purpose (gp2, gp3) EBS volume types?
- Transactional workloads
- Single-instance databases
- Low-latency interactive applications
- Boot volumes
- Development and test environments
Name the EBS volume type considering the following characteristics:
Durability: 99.8% - 99.9%
Volume Size: 4 GiB - 16 TiB
Max IOPS: 64,000 (16 KiB I/O)
Max Throughput: 1,000 MiB/s
Ratio: 50 IOPS per GB
io1 (Provisioned IOPS)
What are the main considerations to take into account when choosing the io1 EBS volume type?
- Multi-attach and NVMe support
- IOPS can be adjusted independently of the volume size
- Consistent low latency and jitter
- Performance cap of 260,000 IOPS and 7,500 MB/s per EC2 instance with four volumes
What are the use cases for the Provisioned IOPS (io1) EBS volume type?
IO-intensive database workloads
Name the EBS volume type considering the following characteristics:
Durability: 99.999%
Volume Size: 4 GiB - 64 TiB
Max IOPS: 256,000 (16 KiB I/O)
Max Throughput: 4,000 MiB/s
Ratio: 500 IOPS per GB
io2 (Provisioned IOPS)
What are the main considerations to take into account when choosing the io2 EBS volume type?
- Multi-attach and NVMe support
- IOPS can be adjusted independently of the volume size
- Consistent low latency and jitter
- Performance cap of 260,000 IOPS and 7,500 MB/s per EC2 instance with four volumes
What are the use cases for the Provisioned IOPS (io2) EBS volume type?
- Sub-millisecond latency
- Sustained IOPS workloads
Name the EBS volume type considering the following characteristics:
Durability: 99.8% - 99.9%
Volume Size: 125 GiB - 16 TiB
Max IOPS: 500 (1 MiB I/O)
Max Throughput: 500 MiB/s
Throughput Optimized HDD (st1)
What are the use cases for the Throughput Optimized HDD (st1) EBS volume type?
- Frequently accessed
- Throughput-intensive sequential workloads (big data, data warehouses, log processing)
What are the main considerations to take into account when choosing the st1 EBS volume type?
- Uses HDD
- Significantly cheaper than SSD-based volume types
Name the EBS volume type considering the following characteristics:
Durability: 99.8% - 99.9%
Volume Size: 125 GiB - 16 TiB
Max IOPS: 250 (1 MiB I/O)
Max Throughput: 250 MiB/s
Cold HDD (sc1)
What are the use cases for the Cold HDD (sc1) EBS volume type?
- Cold data storage
- Infrequently accessed workloadds
- When the lowest cost is a priority
What are the main considerations to take into account when choosing the sc1 EBS volume type?
- Uses HDD
- Significantly cheaper than Throughput Optimized HDD (st1), but less performant
Which EBS volume types are the most cost-effective solutions?
Throughput Optimized HDD (st1) and Cold HDD (sc1)
Which EBS volume type would you consider for streaming, throughput-intensive applications?
Throughput Optimized HDD (st1)
Which EBS volume type would you consider as a boot volume?
- General Purpose (gp2, gp3)
- Provisioned IOPS (io1, io2)
Which EBS volume type would you consider for an application that requires up to 16,000 IOPS?
General Purpose (gp2, gp3)
Which EBS volume type would you consider for an application that requires up to 64,000 IOPS?
Provisioned IOPS (io1, io2)
Which EBS volume type would you consider for an application that requires up to 256,000 IOPS (per instance)?
RAID 0 with Provisioned IOPS (io1, io2) volumes
Which EBS volume type would you consider for an application that requires more than 260,000 IOPS?
Instance store volume
Which EBS feature represents a point-in-time copy of data consumed by EBS volumes, enabling disaster recovery, data migration across regions and accounts, and backup compliance?
EBS Snapshot
What are the main features of EBS Snapshots?
- Incremental in nature, the first is a full backup, then subsequent backups are incremental (each increment is self-sufficient)
- Can be used to migrate data across Availability Zones (AZs) and Regions
- EBS volumes can be created and restored from a snapshot
Which EBS Snapshot feature makes snapshots immediately restored (fully initialized) but has a limit of 50 snapshots per region?
Fast Snapshot Restore (FSR)
What is the EBS Snapshot pricing model?
Billed per GB/month for used data (not allocated)
How does the KMS service perform encryption on an EBS volume?
KMS AWS-managed key (default) or customer-managed key can be used:
- The encrypted data encryption key (DEK) is stored on the EBS volume
- The decrypted data encryption key (DEK) is stored in EC2 host memory
- If EC2 is moved to another host, the decrypted DEK is discarded (EC2 will require KMS to decrypt the DEK stored on the EBS volume and store the decrypted DEK in host memory)
- An EC2 host performs encryption and decryption operations on data, acting as a layer between the EBS volume and the EC2 instance, this ensures that data is encrypted at rest and only exists in unencrypted form in the EC2 host’s memory
- The same DEK creates encrypted snapshots of encrypted EBS volumes
- The same DEK encrypts EBS volumes created from encrypted snapshots
- KMS is used to generate a unique DEK per volume
Each EBS volume (created from scratch) uses one unique DEK (snapshots created from that volume and volumes created from the snapshots all use the same DEK)
Can you change an encrypted EBS volume to be unencrypted?
No, you cannot change the volume to be unencrypted, but you can clone the data to an unencrypted volume
Is the operating system of an EC2 instance aware of EBS volume encryption?
The instance OS is unaware of encryption; encryption happens between the host (where the EC2 instance resides) and the EBS volume
What is the minimum and maximum baseline performance of AWS EBS gp2 in relation to volume size?
- Minimum 100 IOPS (for volumes up to 33.33 GiB)
- Maximum 3,000 IOPS (for volumes 5.334 TiB and larger)
How does the baseline performance of AWS EBS gp2 scale with volume size?
Linearly at 3 IOPS per GiB
What is the IOPS provisioning ratio for AWS EBS io1 volumes?
Ratio is 50:1
for a 100 GiB io1 volume, up to 5,000 IOPS can be provisioned
What is the IOPS provisioning ratio for AWS EBS io2 volumes?
Ratio is 1,000:1
for a 256 GiB io2 volume, up 256,000 IOPS can be provisioned
Does AWS EBS support encryption for data in-flight and at rest?
Yes, AWS EBS supports encryption for data both in-flight and at rest
Can you disable encryption for individual EBS volumes or snapshots if encryption by default is enabled for a region?
No, if encryption is enabled for a region, you cannot disable it for individual volumes or snapshots in that region
