How to setup and manage Disaster Recovery
Our Disaster Recovery section gives you an option to setup and manage some aspects of the Disaster Recovery scenarios described in the AWS Disaster Recovery Overview article.
Using our wizard for Disaster Recovery, you are able to make setup across AWS Regions as well as across AWS Accounts.
Using our wizard, you are able to select source and destination regions and accounts as well as instances you want to replicate to Disaster Recovery region. Additionally, you receive options to define the Disaster Recovery parameters for each resource.
Let us review the options available under Disaster Recovery wizard step by step:
General Tab
Name – Name of your Disaster Recovery setup; the name must be unique across all of your DRs under the same account
Source Region – AWS region to replicate resources from
Destination Region – AWS region that is setup as the Disaster Recovery region; it is the region where selected resource from source region is replicated to
Setup Disaster Recovery under different AWS account – Check this option to transfer your AWS EC2 resources to different AWS account
Destination Account – AWS account you want to setup/transfer EC2 resources to.
Resource Selection Tab
The Resource Selection tab lists all Instances and Elastic Load Balancers currently accessible in source region. You can select any Instance you want to replicate to Disaster Recovery region. Also, you can select Elastic Load Balancer you want to setup in DR region.
When you select ELB, you have to select at least one Instance which is currently attached to that ELB. (This option applies only to ELB, which has already attached instance(s)).
Notes:
For ELB while using SSL, all certificates need to be manually copied and setup in destination Disaster Recovery region.
Most attributes of the Instances from source region are replicated to the destination region including: Security Groups, Local IP, Source Destination Check, and Sub-networks; along with all VPC parameters, such as Subnets, Route Tables, Internet Gateway, and DHCP Options.
Resource Configuration Tab
The resource configuration tab allows you to specify disaster recovery option for each Instance selected on previous tab.
Options that can be setup for each Instance include:
Instance Name – Identification of the Instance selected on the previous tab (not editable)
Action Type – There are three possible options to select:
-Only Copy: Initial Setup Action: this option creates AMI of the Instance from the source region and copies it over to the destination region. The new Instance is not launched from that AMI. There are additional options available for this type of replication described later in this document.
Scheduler Action: create and copy a new AMI image of the source Instance to the destination region. Deregister previous AMI image in destination region.
-Replace Instance: Initial Setup Action: this option creates the source Instance, copies it to the destination region, and launches a new Instance based on that image. The additional actions can be taken after Instance launch (if applicable), such as: register under ELB, assign EIP, stop Instance.
Scheduler Action: the process is similar to the one in initial setup with additional steps. Before the new Instance is launched, the old one will be terminated.
if the replacing Instance was attached to ELB or was setup as NAT server, then load balancer or route table will be updated adequately.
-Update Volume: Initial Setup Action: the initial action is the same as in the Replace Instance option.
Scheduler Action: the snapshot of the volume is taken and copied over to the destination region. The old volume attached to the Instance in destination region is detached and deleted. The newly copied snapshot is converted into volume and attached to the Instance.
Instance Type – this option lets you specify the type of the EC2 Instance in destination region. The new Instance can have different size from source Instance.
AMI Action – there are two options available:
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New: this option triggers creation of new image of the source Instance and copies it to destination region.
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AMI ID: if the image of the selected Instance was already copied to the destination region, you can skip creation of the new image and use one in Disaster Recovery region.
Keep Running – this option allows you to specify if the Instance after launch is supposed to be running or be shutdown.
Allocate EIP – when this option is checked off, the new Elastic IP is allocated and associated with the newly launched Instance. This option is active only when selected Instance in the source region has associated EIP.
Only Setup – this option lets you specify whether the selected Instance is created only during initial disaster recovery setup or should also be updated based on the scheduler.
Delete – this option lets you delete the Instance from the list. When you edit existing setup, this option does not cause deletion of the Instance in destination region, but does remove it from scheduler list.
Volumes Configuration Tab
The volume configuration tab is active only when at least one of the Instances on previous tab has been selected as an Update Volume action type.
Instance Name – Name of the selected Instance.
Instance ID – ID of the selected Instance.
Stop Instance – This option lets you specify if you want to stop Instance before the old volume is replaced with the new one. This option should be checked when the selected volume(s) contain database or other data used by any application where sudden loss of access to hard drive could cause potential issue. When the root drive is selected (/dev/sda1) the Instance must be stopped regardless of the chosen options.
Click the arrow on the right to expand the list of the volumes attached to the given Instance.
Update – When checked, volume in Disaster Recovery region is updated based on the schedule.
Name – Name or drive path of the volume.
Volume ID – ID of the volume.
Size – Size of the volume.
Volume Type – This option lets you choose what type of EBS volume is restored during scheduled update process.
IOPS – Allows specification of new IOPS of the EBS volume. This option is active only when the selected Volume Type is Provisioned IOPS.
Suspend – This option lets you suspend scheduled update of the EBS volume.
Note: for each Instance you must check at least one volume, otherwise the wizard won’t let you continue to the next step.
AZ Mapping Tab
Availability Zone mapping tab provides you an option to map zones from source region to the destination region. This feature is helpful when your source resources are spread between multiple availability zones.
Schedule Tab
The Schedule tab allows you to setup interval of how frequently you want to update your resources in Disaster Recovery region.
If you are planning to setup or transfer your EC2 resources as a one time process, you can skip schedule by checking the Don’t use scheduler to update Disaster Recovery resources on regular basis option.
Occur – This option allows you to select occurrence of the updates: choose Hourly, Daily, or Monthly frequency. Each of the occurrences has additional options described below:
Hourly:
Occurs Every x Hours: specify the interval of occurrence in hours
Starting At and Ending At: specify the time range when the update should take place, or leave blank for 24h range period
Daily:
Days: select days on which the update occurs
Time: select time at which the update occurs
Monthly:
Occurs Every x Day of the Month: the update occurs once a month on the specified day of the month
Time: time when the update occurs
Finish Tab
After clicking the Finish button, the new setup is created. The process of initial setup of the disaster recovery region starts within 5 minutes after completion of the wizard. You cannot modify any options of your Disaster Recovery plan until the initial setup is finished.
All Disaster Recovery plans are listed above the wizard. You can track progress of the setup by refreshing the list.
For each Disaster Recovery plan, you can execute the following options:
Edit – this option allows you to change some of the parameters of the previously setup Disaster Recovery plan
Suspend/Resume – this option allows you to suspend or resume the scheduler
Delete – delete existing Disaster Recovery plan; this option does not delete any resources in destination region
Boot – this option launches Instances marked as Only Copy under Disaster Recovery plan
CloudFormation – this option outputs the CloudFormation script with setup of all Instances marked as Only Copy
Resource Log – show mapping between source and destination objects
Error Log – show list of errors during setup or update
Updates Log – show list of objects that were updated based on the schedule
Note:
Both Boot and CloudFormation options are available only if at least one Instance was marked as Only Copy on configuration tab in the wizard.
When you use Cloud Formation script, there is not an option to attach new Instance to Elastic Load Balancer.
Also, in both cases the route table is not updated even if the created Instance serves as the NAT server.
General Note:
Despite Disaster Recovery plan setup for each Instance, whenever at least one of them is inside VPC, then the entire VPC is recreated in destination region with the same attributes.
Each Elastic Load Balancer selected in the wizard is automatically recreated in the destination region. If ELB is using SSL connection, all certificates need to be manually setup under the new ELB.