Storage Flashcards
Can you mount EBS across AZs?
No, to ensure the lowest latency this is not possible
When to use provisioned IOPS?
When more than 10000 IOPS are needed
What is an IOPS?
Measurement how many read/write actions can happen in a second - based on a standard package size
What is throughput?
product of packet size and IOPS
What are Bursting IOPS and Throughput
Burst: IOPS not used are generating credits that can be used to burst up to 3000 IOPS and therefore a higher throughput
What must be considered for IOPS for EC2 and EBS?
Even though EBS volumes can have a high amount of IOPS it might be limited by the EC2 instance
How to share (un)encrypted snapshots
Public shared snapshots can only be unencrypted.
Encrypted volumes can be shared to a specific account as long as the Customer Master Key is provided
How are EFS volumes sized?
Automatic sizing
When to (not) use S3-IA?
If called < 20 times/yr, smaller than 4Kb and listed shorter than 30days
How to use Cross-Region Replication?
Versioning must be enabled. (Files are not syncronized to the regions, just copied)
CRR can be used for different accounts
What is the vault lock?
When used a file cannot be deleted until a certain amount of time (10yrs e.g.)
Describe the (three) Storage Gateway Options
File interface (Access via Network File System) Volume interface (Data is accessed on local storage) Tape interface (Connected to existing backup method - and then stored in S3)
What is the time interval at which EFS metric data gets sent to CloudWatch?
CloudWatch receives EFS metric data in one-minute intervals.
Which are not replicated by default using S3 CRR?
Objects that existed before replication
Lifecycle policies
Server-side encryption using KMS-managed keys
Server-side encryption using customer-provided keys
What is the limitation for HDD storage?
You cannot use them for a boot device
When to use the cold HDD (sc1)
Infrequent access with minimized storage costs
How to get 6000 IOPS
Using a volume size of 2000GB (2000 x 3IOPS)
When is Pre-Warming an EBS volume neccessary?
In the past a new volume needed to be warmed in order to ensure the maximum capacity.
New volumes do not require this anymore.
However: if a volume is restored from S3 the blocks need to be initialized this causes some latency issues.
There a pre warming could be done.
What are the volume status checks?
OK
WARNING
Degraded (performance under expectation)
Severely degraded (performance highly under expectations)
IMPARED
Stalled (performance severely under expectations)
Not Available (I/O is not measured - volume is offline)
INSUFFICIENT_DATA
Can you modify an attached EBS volume?
Yes, it is possible to change the type, size and IOPS on an attached volume without detaching it.
What is Eviction? (Elasticache)
When there’s no space and a file is added, an old file needs to be deleted
What should be done in terms of Eviction on Elasticache?
Memcache(d): Scale out or Up (increase RAM)
Redis: Scale out (add read replicas)
How many IOPS are given per GB for gp2 and io2
gp2: 3 (16000 max)
io1: 50 (64000 max)
Describe the two consistency models in S3
Read after Write consistency for PUTS on new objects
Eventual Consistency for PUTS on existing object and DELETES
What are you charged for in S3?
- Storage per GB
- Requests (GET, PUT)
- Storage Management (like Tagging)
- Accelerated Traffic
- Egress traffic
What is the file gateway?
- uses S3 for storage
- accessed with NSF or SMB and therefore appears as a normal network storage
- has the all the advantages of S3
What is the volume gateway?
- cloud backed storage
- iSCSI
- two types:
- Gateway Stored Volumes: Storage is local, backup in AWS (as EBS snapshots)
- Gateway Cached Volumes: S3 as primary storage, files are cached locally
What is Tape Gateway?
- Data Archive in Glacier
- Can integrate with existing tape infrastructure
Can a policy be attached to an S3 object?
No, only to buckets+
What is the difference between a bucket policy and iam user policy?
“Who can access this S3 resource?”
“What can this user do in AWS?”
What is an advantage of a bucket policy?
You can grant cross-account access to S3 bucket w/o IAM
What is an S3 Access Control List (ACL)?
Precursor to Bucket Policies.
Can be on a Bucket, Folder or Object Level
Can only grant, not deny access
Has predefined groups (All users, All auth. users)
S3: What is the maximum upload size for a single PUT operation to S3, and what is the maximum object size limit?
5GB for a PUT, 5TB for a single object.
A user has launched a dedicated EBS-backed instance. You are curious where the EBS volume for this instance will be created.
The EBS volume will not be created on the same tenant hardware assigned to the dedicated instance.
A root AWS account owner is trying to understand various options to set the permission to Amazon S3. Which option below is not an access control mechanism in Amazon S3?
- S3 Bucket access control list
- S3 Object access policy
- IAM User access policy
- S3 Bucket access policy
S3 Object access policy
Amazon S3 provides a set of operations to work with the Amazon S3 resources. Managing S3 resource access refers to granting others permissions to work with S3. There are three ways the root account owner can define access with S3:
In AWS Storage Gateway, using a tape gateway’s virtual tape library (VTL), you can cost-effectively and durably archive backup data in____
Amazon Glacier
After a retrival request to Glacier, how can the data be accessed
The retrieval request creates a temporary copy of your data in the S3 RRS or S3 Standard-IA storage class while leaving the archived data intact in S3 Glacier
Which types of AWS Storage Gateway offer local caches for frequently accessed data? (Choose 2 answers)
Cached volume gateways
File gateways
Both file gateways and cached volume gateways provide local caches to store frequently accessed data. Stored volume gateways keep all files locally, so all stored data can be retrieve with reduced latency. Tape gateways are an archival method, and not ideal for data that needs to be readily available.
