AWS: EBS at a Glance

Mar 26, 2019

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Elastic Block Store- EBS
Volume Types	4 volume types	SSD – Solid State Drive				HDD – Hard Disk Drive
		General Purpose – gp2		Provisioned IOPS – io1		Throughput Optimized HDD – st1		Cold HDD – sc1
		Size	1GB – 16TB	Size	4GB – 16TB	Size	4GB – 16TB	Size	4GB – 16TB
		Max IOPS	16000	Max IOPS	64000 – For Nitro 32000 – For All other	Max IOPS	500	Max IOPS	250
		Min IOPS	100	Min IOPS		Min IOPS		Min IOPS
		IOPS/GB	3	IOPS/GB	50
		Max Throughput	250 MiB/s	Max Throughput		Max Throughput	500 MiB/s	Max Throughput	250 MiB/s
		MiBs/GB		MiBs/GB		MiBs/GB	40	MiBs/GB	12
		Use Cases: transactional, IOPS-intensive database workloads, boot volumes, and workloads that require high IOPS				Use Cases: throughput-intensive and big-data workloads, large I/O sizes, and sequential I/O patterns.
		Note: 5333 GB will give max IOPS, adding more space to volume does not help you in terms of IOPS		Note: We can Assign IOPS manually as per volume’s GB, however not more than 50 IOPS/GB rate.
Snapshot	Scope in terms of Region and AZ	– Snapshots can be copied within or to other regions. – Using a snapshot, volumes can be created in any AZ within the same region as of Snapshot.
Migration	Scope in terms of Region and AZ	– Volumes are locked to specific to an AZ.
	To migrate to Different AZ or Region	– Create an EBS Snapshot of the Volume. – Copy Volume to Different Region(if you willing to migrate to Diff Region) – Create new EBS volume from the snapshot in AZ you are willing to have.
Encryption	Encryption Types	KMS (AES-256)
	Encrypted EBS Volume	– Data at rest is encrypted inside the volume. – All the data in flight moving between the instance and the volume is encrypted. – All Snapshots are encrypted. – All Volumes created from Snapshot are encrypted.
	Encrypt an Unencrypted volume	– Create an EBS Snapshot of the Volume. – Encrypt the EBS snapshot (Using Copy). – Create new EBS volume from the snapshot – The volume will also be Encrypted. – Attach the Encrypted Volume to the Original Instance.
RAID	Compatibility	– Depends on whether OS supports or not – Linux and Windows OS Support RAID.
	Configurations	RAID 0	– Can combine more than 1 EBS volumes to single RAID 0 Array. – The resulting size of a RAID 0 array is the sum of the sizes of the volumes within it. – The bandwidth is the sum of the available bandwidth of the volumes within it. – For example, two 500 GiB Amazon EBS io1 volumes with 4,000 provisioned IOPS each will create a 1000 GiB RAID 0 array with an available bandwidth of 8,000 IOPS and 1,000 MB/s of throughput – Use Case: When I/O performance is more important than fault tolerance; for example, as in a heavily used database (where data replication is already set up separately). – Disadvantage – Loss of a single volume results in a complete data loss for the array.
		RAID 1	– RAID 1 array offers a “mirror” of your data for extra redundancy. – The resulting size and bandwidth of a RAID 1 array is equal to the size and bandwidth of the volumes in the array. – For example, two 500 GiB Amazon EBS io1 volumes with 4,000 provisioned IOPS each will create a 500 GiB RAID 1 array with an available bandwidth of 4,000 IOPS and 500 MB/s of throughput. – Use Case: When fault tolerance is more important than I/O performance; for example, as in a critical application. – Disadvantage -Does not provide a write performance improvement; requires more Amazon EC2 to Amazon EBS bandwidth than non-RAID configurations because the data is written to multiple volumes simultaneously.
		RAID 5	– Not recommended by AWS.
		RAID 6	– Not recommended by AWS.
Instance Store	– Instances not coming with Root EBS volumes having their own instance store (ephemeral storage). – Instance store is physically attached to the machine. – Advantages: Better I/O as no network latency. Good for buffer / cache/ scratch data/ temporary content. Data Survives Reboot/restart – Not Stop and Start!!!– Disadvantages: Data will be lost upon instance stop or termination. Manually cannot resize an instance store. No automated backup.
Additional Notes: – Data is stored as Blocks. – EBS is a network drive. – Provisioned IOPS volumes can achieve single digit millisecond latencies. – You can stripe multiple volumes together to achieve up to 75,000 IOPS or 1,750 MiB/s when attached to larger EC2 instances. However, performance for st1 and sc1 scales linearly with volume size so there may not be as much of a benefit to stripe these volumes together.