I understand that EBS volumes that are restored from snapshots need to be initialized.
Let's say I create an AMI from an EBS snapshot(s).
When I launch a new instance using that AMI, will I need to initialize each volume before I get consistent latency?
When you create an instance from AMI which has EBS based volumes as storage, your instance creates new volume from this volume and continues with launch.
When you use snapshots as source to launch your instance, AWS need to pull these snapshots and write it to volume and then continue with the launch. In this case, pull storage blocks from S3 and write to volume will be the latency some users want to avoid. This is the case where pre-warming is suggested by AWS.
Related
I have a few AMIs stored with snapshot associated with their storage definitions. However, the volumes that are associated with those snapshots have been deleted to save costs.
Can the AMIs still be used?
Yes, because snapshot is a backup of your volume. The original volume does not have to exist for the snapshot to be useful. You can always create a volume from a snapshot.
If you want to double check this, you can spin up basic t2.micro instance, take it snapshot, delete the instance and any associated volumes (root volume will be automatically deleted). Then you can launch new instance from the snapshot created.
Scenario
I currently have an EC2 instance with a root EBS volume attached to it of 30gb and i have some files stored in that EBS
If i delete the EC2 instance and have delete on termination false then EBS persists.
Desired outcome
I want to provision a new EC2 (provisioned by auto scaling group) instance such that it uses the old EBS volume as its root volume which was detached as a result of me terminating the old instance
Note
I want to have the liberty of choosing OS of newly provisioned EC2 so creating an AMI does not work
You cannot directly launch a new Amazon EC2 instance with an existing Amazon EBS volume. Instead, you would need to:
Launch a new Amazon EC2 instance with a new root volume
Stop the instance
Detach the root volume
Attach the 'old' EBS volume
Start the instance
Storing data in root EBS volume might be a bad idea to start with.
Consider one of the following:
Mount another EBS volume to the instance to store required data only.
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-using-volumes.html
best performance, highest cost/effort, but your application doesn't
change a bit.
Create EFS and mount it to your instances. https://docs.aws.amazon.com/efs/latest/ug/mounting-fs.html -
reasonable effort, minimal if any changes to the application.
Store data in S3. Ideal from price standpoint; requires changes to the application.
I created several snapshots from volumes of my instances months ago. Today I had to restore an instance based on a snapshot, but this instance does not contain any of my data, it is a clean version of Ubuntu, exactly as the first time I created the instance.
How do I restore my data?
thanks
In AWS there are two snapshot options:
1- Snapshot: You can use snapshots to capture a point-in-time state of your individual volumes.
2- Amazon Machine Image (AMI): You can use an AMI to capture a point-in-time state of your whole EC2 instance (VM), including all of its volumes.
So, difference is that snapshot is on individual volume level and AMI is the entire instance. Under the hood, AMI takes snapshots of all attached volumes and you can see those snapshots in the corresponding Snapshots page in AWS Management Console.
So to be clear, did you create an AMI from you Ubuntu instance and restored the same AMI? Or did you create a snapshot from one or more of its volumes? In that case, how did you restore it?
If you only take a snapshot of one or more of the volumes, after you restore your snapshots into new volumes attached to an instance, you should also remember to mount those volumes. But if you use an AMI, mounting may not be required, as long as you have added your volumes in the /etc/fstab.
Is there any way to figure out which region an AWS EBS snapshot lives in?
A collaborator shared an ebs snapshot with me but I'm having a very slow transfer rate when I attached it to my instance (which is in USEAST-1d). I was wondering if the snapshot lived somewhere else but couldn't find a way to check it.
Snapshots operate on Amazon EC2 regional scope. You cannot create a volume from a snapshot residing in different region. Since you are able to create a volume in US-East-1A, i assume your snapshot also resides on US-East region.
Also as eric mentioned it is not possible to attach a snapshot to an EC2 directly, you have to create an EBS volume and then attach the volume to EC2 instance
I am trying to create a backup mechanism for our server, so that if my system crashes, I should be able to create the whole system by running a single script
After going through Amazon documentation, this is my understanding of creating a backup and restoring
Backup
Create a AMI Image (this can be updated monthly)
Create a snapshot (This can be done using a daily script creating a snapshot)
Restore (A script to)
Create an EBS instance using AMI
Attach the EBS volume to Instance created
Now my Questions are
Is it the best way to take a backup and restore?
Do we actually need to backup 2 things, AMI and EBS volume (using snapshot), Can we just keep snapshots?
I understand this cannot work for a local instance store instance, as there is no snapshot functionality. So how can I create a backup and restore process for local instance store instances?
As I could not find any better alternative, I am sticking with the initial approach.
For EBS
Backup:
Create a AMI Image (this can be updated monthly).
Create a snapshot (This can be done using a daily script creating a snapshot).
Restore (A script to)
Create an EBS instance using AMI.
Attach the EBS volume to Instance created.
For instance store, I am only keeping the application (no database), so no need to keep a backup of that.
EBS Snapshots are an excellent way to create backups.
You can perform frequent Snapshots of your EBS Volumes via scripts. Weekly, Daily, Hourly, or as frequently as your Credit Card will allow. The only limit is around how many simultaneous snapshots you can be doing - when you hit that, the EBS API will start giving back errors until a few of the in-flight operations complete.
Snapshots can also be copied from Region to Region in order to provide backup against a catastrophic event.
When you snapshot an EBS volume, that snapshot is of the entire volume. Even if it was created from an AMI, your snapshot contains everything you need to create a new instance of the volume. You can pretty easily try this yourself.
If your instances are Linux based, there is no need to create an AMI if you're taking snapshots. You can create the AMI on the fly, from the snapshots, when you need to recover. If you got that process automated, it's pretty easy to do.
In Windows there is a limitation not allowing to launch an EC2 instance from a snapshot, so AMIs must be used. There are ways to workaround that limitation: You can check out the this post I wrote in our company's blog:
http://www.n2ws.com/blog/3-ways-ec2-windows-backup-and-recovery.html
I would suggest to use Auto Scaling in addition to EBS snapshots. If Instance is dying because of Hardware failure or it's scheduled for retirement by Amazon, Auto Scaling will start new Instance automatically.
But in this case, you have to setup NAS for your dynamic data. Depending on Server Load, the number of running Instances will be different and all your scaling servers must mount NAS storage which is shared across them.
Your Database should be on separate server or servers as well. Or you might want to use Amazon RDS as it has great auto-backup / Point-In-Time-Restore features, but you have to pay extra for that.
1) Yes.Snapshot is best way to backup and restore EBS volumes.
2) Depends, if you have the root volume as EBS backed AMI, then you can snapshot them as well and improves the manageability
3) Rsync and AMI is the option available for instance store