Migration Flashcards
6Rs - Rehosting - lift and shift
- Migrate entire VM
- AWS VM import/export
- AWS Server Migration Service
6Rs - Replatforming
- Migrate your DB to RDS
- Migrate java app to beanstalk
6Rs - Repurchase
- Move to different produce while moving to the cloud
6Rs - Refactoring & Rearchitecture
- Decoupling using SQS/SNS
- Move to serverless
- Use S3 for storing files
6Rs - Retire stuff not needed
- Helps reducing surface attack
6Rs - Retain
- Do nothing to migrate to cloud
AWS Storage Gateway
- Bridge between on-prem and cloud data in S3
- Helps with disaster recovery, backup & restore, tiered storage
AWS Storage Gateway File Gateway
- You get a FG appliance - VM, that is a bridge between NFS mount and S3 bucket
- Cached, saves trips to S3 and costs
- Can be accessed using both NFS and SMB
- Requires IAM access to S3 Service
File Gateway Use cases
- FG mounts for on-prem and EC2 to facilitate migration
- Second read-only mount, low latency get files
- Files in FG can go through Lifecycle policies, cost savings
- Can have file version control, if S3 versioning enabled
File Gateway - WORM
- Object lock
- If there are changes, File Gateway creates a new version without affecting original locked or prior versions
Volume Gateway
- iSCSI - backed by S3
- Cached Volumes: low latency access for most recent on-premise, full data on S3 - 1TB per volume
- Stored Volume: Entire dataset is on premise, scheduled backups to S3 - 0.5TB per volume
- To access data create EBS snapshots from volumes and restore a EBS
Tape Gateway
- To access data need to restore entire tape
- Virtual Table Library protocol backed by S3 Glacier
Snowball Edge
For compute on the data:
- Supports EC2 AMI
- Lambda
DB Migration Service
- Quick, secure, resilient, self healing
- Source DB remains available during migration
- Oracle to Oracle
- Oracle to MySQL (Schema Conv Tool)
- Oracle to Redshift (SCT)
- Continuous Data Replication using CDC (Streams changes)
- Requires EC2 to perform replication tasks
DBMS Network
- VPC Peering, VPN (site-2-site, software), DXConnect
DBMS Blobs
Only if Blobs have primary key
Snowball + DMS
- Using SCT download to Snowball Edge
- Ship Edge device to AWS
- Load data to S3
- DMS to replicate from S3 to target DB
- CTC to apply deltas since snowball got shipped
AWS Application Discovery Service
- Gather info about on-prem data centers
- Agentless: open virtual appliance pkg on VMware host
- OS agnostic
- Agent: system configuration, network connections
- Results expored in CSV or viewed in AWS Migration Hub
- Can query data using Athena
- Server Migration Service
- Rehosting, entire VM, improvement over EC2 import/export
- One time migrations or replication of live on-prem servers every interval
Disaster Recover
- RPO - Data Loss.
- RTO - Downtime
Backup and Restore
High RPO and High RTO
- Regular backups lowers RPO
Pilot Light
- Still cost effective, for critical systems
- Lower RPO and Lower RTO
Warm Standby
- Full system running, but at minimum size
- Upon disaster can scale to production load
- More costly
- Lower RPO and Lower RTO
Hot Hot Mutli Side
- Most expensive
- Lowest RTO and RPO
EFS Source of Data
EFS cannot use an S3 bucket as a source of data
Snowball sizes
Snowball has two types of device model: 50 TB and 80 TB, you can only store a total of 42 TB and 72 TB respectively based on their usable capacity limits. You have to use AWS Snowball Edge instead.
The maximum size of a single file that can be delivered through Amazon CloudFront is
20 GB
