AWS Storage Service - EBS Flashcards
EBS Overview
Block level storage volumes for use within EC2 instances
well-suited for use as the primary storage for file systems, databases, or for any applications that require fine granular updates and access to raw, unformatted, block-level storage.
well-suited for both database style applications (random reads and writes) and to throughput-intensive applications (long, continuous reads and writes)
new EBS volumes receive their maximum performance the moment that they are available and do not require initialization (formerly known as pre-warming). however, storage blocks on volumes that were restored from snapshots must be initialized (pulled down from S3 and written to the volume) before you can access the block
Termination protection is turned off by default and must be manually enabled (keeps the volume/data when the instance is terminated)
you can have up to 5,000 EBS volumes by default
you can have up to 10,000 snapshots by default
EBS Overview
Types of EBS volumes
General purpose SSD (gp2)
base performance of 3IOPS/GIB with the ability to burst to 3,000 IOPS for extended periods of time. Support up to 16,000 IOPS and 250 mb/s of throughput. the burst duration of a volume is dependent on the size of the volume, the burst IOPs required, and the credit balance when the burst begins. Burst IO duration is computed using the following formula: burst duration = (credit balance)[(burst IOPS)-3(volume size in GiB)]
If your gp2 volume uses all of its I/O credit balance, the maximum IOPS performance of the volume remains at the baseline IOPS performance level and the volume’s maximum throughput is reduced to the baseline IOPS multiplied by the maximum I/O size. Throughput for gp2 volume can be calculated using the formula: Throughput in MiB/s=(volume size in GiB) (IOPS per GiB)*(I/O size in KiB)
Provisioned IOS SSD (io1)
designed for I/O intensive workloads, particularly database workloads, which are sensitive to storage performance and consistency. Allows you to specify a consistent IOPS rate when you create the volume
Throughput Optimized HDD (st1)
low-cost magnetic storage that focuses on throughput rather than IOPS. Throughput of up to 500 MiB/s. Subject to throughput and throughput-credit caps, the available throughput of an st1 volume is expressed by the following formula:
(volume size)(credit accumulation rate per TiB) = Throughput
Cold HDD (sc1) Low cost magnetic storage that focuses on throughput rather than IOPS. Throughput of up to 250 MiB/s
Types of EBS volumes
Types of EBS volumes
General purpose SSD (gp2)
base performance of 3IOPS/GIB with the ability to burst to 3,000 IOPS for extended periods of time. Support up to 16,000 IOPS and 250 mb/s of throughput. the burst duration of a volume is dependent on the size of the volume, the burst IOPs required, and the credit balance when the burst begins. Burst IO duration is computed using the following formula: burst duration = (credit balance)[(burst IOPS)-3(volume size in GiB)]
If your gp2 volume uses all of its I/O credit balance, the maximum IOPS performance of the volume remains at the baseline IOPS performance level and the volume’s maximum throughput is reduced to the baseline IOPS multiplied by the maximum I/O size. Throughput for gp2 volume can be calculated using the formula: Throughput in MiB/s=(volume size in GiB) (IOPS per GiB)*(I/O size in KiB)
Provisioned IOS SSD (io1)
designed for I/O intensive workloads, particularly database workloads, which are sensitive to storage performance and consistency. Allows you to specify a consistent IOPS rate when you create the volume
Throughput Optimized HDD (st1)
low-cost magnetic storage that focuses on throughput rather than IOPS. Throughput of up to 500 MiB/s. Subject to throughput and throughput-credit caps, the available throughput of an st1 volume is expressed by the following formula:
(volume size)(credit accumulation rate per TiB) = Throughput
Cold HDD (sc1) Low cost magnetic storage that focuses on throughput rather than IOPS. Throughput of up to 250 MiB/s
Types of EBS volumes
Monitoring
cloudwatch monitoring two types: basic and detailed monitoring
volume status checks provide you the information that you need to determine whether your EBS volumes are impaired, and help you control how a potentially inconsistent volume is handled. list of statuses include: ok- normal volume, warning-degraded volume, impaired - stalled volume, insufficient data - insufficient data
volume events include a start time that indicates the time at which an event occurred, and a duration that indicates how long I/O for the volume was disabled. the end time is added to the event when I/O for the volume is enabled
Volume events are: awaiting action: enable IO IO enabled IO auto-enabled Normal Degraded severely degraded stalled
Monitoring
Monitoring
cloudwatch monitoring two types: basic and detailed monitoring
volume status checks provide you the information that you need to determine whether your EBS volumes are impaired, and help you control how a potentially inconsistent volume is handled. list of statuses include: ok- normal volume, warning-degraded volume, impaired - stalled volume, insufficient data - insufficient data
volume events include a start time that indicates the time at which an event occurred, and a duration that indicates how long I/O for the volume was disabled. the end time is added to the event when I/O for the volume is enabled
Volume events are: awaiting action: enable IO IO enabled IO auto-enabled Normal Degraded severely degraded stalled
Monitoring
EBS Snapshots
back up the data on your EBS volume to S3 by taking point in time snapshots
snapshots are incremental backups which means that only the blocks on the device that have changed after your most recent snapshot are saved. This minimizes the time required to create the snapshot and saves on storage costs by not duplicating data.
when you delete a snapshot only the data unique to that snapshot is removed
you can share a snapshot across AWS accounts by modifying its access permissions
you can make copies of your own snapshots as well as snapshots that have been shared with you.
a snapshot is constrained to the region where it was created
EBS snapshots broadly support EBS encryption
you can not delete a snapshot of the root device of an EBS volume used by a registered AMI. You must first deregister the AMI before you can delete the snapshot
Each account can have up to 5 concurrent snapshot copy requests to a single destination region
user-defined tags are not copied from the source snapshot to the new snapshot
snapshots are constrained to the region in which they were created. To share a snapshot with another region, copy the snapshot to that region
snapshots that you intend to share must instead be encrypted with a customer CMK
EBS Snapshots
EBS - optimized instances
provides the best performance for your EBS volumes by minimizing contention between EBS I/O and other traffic from your instance
EBS-optimized instances deliver dedicated bandwidth between 500 mbps and 60,000 mbps to EBS
for instance types that are EBS-optimized by default, there is no need to enable EBS optimization and no effect if you disable EBS optimization
EBS - optimized instances
Pricing
you are charged by the amount you provision in GB per month until you release the storage
provisioned storage for gp2 volumes, provisioned storage and provisioned IOPS for io1 volumes, provisioned storage for st1 and sc1 volumes will be billed in per-second increments with a 60 second minimum
with provisioned IOPS SSD (io1) volumes, you are also charged by the amount you provision in IOPS per month
after you detach a volume, you are still charged for volume storage as long as the storage amount exceeds the limit of the AWS free tier. You must delete a volume to avoid incurring further charges.
snapshot storage is based on the amount of space your data consumes in S3
copying a snapshot to a new region does incur new storage costs
when you enable EBS optimization for an instance that is not EBS-optimized by default, you pay an additional low, hourly fee for the dedicated capacity
Pricing
