I'm trying to mount the same volume for a Beanstalk build but can't figure out how to make it work with the volume-id.
I can attach a new volume, and I can attach one based on a snapshot ID but neither are what I'm after.
My current .ebextension
commands:
01umount:
command: "umount /dev/sdh"
ignoreErrors: true
02mkfs:
command: "mkfs -t ext3 /dev/sdh"
03mkdir:
command: "mkdir -p /media/volume1"
ignoreErrors: true
04mount:
command: "mount /dev/sdh /media/volume1"
option_settings:
- namespace: aws:autoscaling:launchconfiguration
option_name: BlockDeviceMappings
value: /dev/sdh=:20
Which of course will mount a new volume, not attach an existing one. Perhaps snapshot is what I want and I just don't understand the terminology here?
I need the same data that was on the volume when the autoscaling kicks in to be on each EC2 instants that scales... A snapshot would surely just be the data that existed at the point the snapshot was created?
Any ideas or better approaches?
Elastic Block Store (EBS) allows you to create, snapshot/clone, and destroy virtual hard drives for EC2 instances. These drives ("volumes") can be attached to and detached from EC2 instances, but they are not a "share" or shared volume... so attaching a volume by ID becomes a non-useful idea after the first instance launched.
EBS volumes are hard drives. The analogy is imprecise (because they're on a SAN) but much the same way as you can't physically install the same hard drive in multiple servers, you can't attach an EBS volume to multiple instances (SAN != NAS).
Designing with a cloud mindset, all of your fixed resources would actually be on the snapshot (disk image) you deploy when you release a new version and then use to spawn each fresh auto-scaled instance... and nothing persistent would be stored there because -- just as important as scaling up, is scaling down. Autoscaled instances go away when not needed.
AWS has Simple Storage Service (S3) which is commonly used for storing things like documents, avatars, images, videos, and other resources that need to be accessible in a distributed environment. It is not a filesystem, and can't properly be compared to a filesystem, because it's an object store... but is a highly scalable and highly available storage service that is well-suited to distributed applications. s3fs allows an S3 "bucket" to be mounted into your machine's filesystem, but this is no panacea. That mechanism should be reserved for back-end process use, if you use it at all, because it's not appropriate for resources like code or templates, and will not perform as well for serving up content as S3 will perform if used as designed, with clients directly accessing it over https. You can secure the content through more than one mechanism, as documented.
AWS also now has Elastic File System (EFS) which sets up an array of storage that you can mount from all of your machines, using NFS. AWS provides the NFS server and the back-end storage. Unlike EBS, you do not need to know how much storage to provision up front, because it scales up and down based on what you've stored, billing you This service is still in "preview" as of this writing, so should not be used for production data.
Or, you can manually configure your own NFS server and mount it from the autoscaling machines. Making such as setup fail-safe is a bit tricky, though.
Related
I'm trying AWS auto-scaling for the first time, as far as I understand it creates instances if for example my CPU Utilization reaches critical level, that I define.
So I am curious, after I lunch my instance I spend a fair amount of time configuring it and copying the data, if AWS auto-scales my instance how will it configure the new instances and move the data to it?
You can't store any data that you want to keep on an instance that is part of an autoscaling group (well you can, but you will lose it).
There are (at least) two ways to answer your question:
Create a 'golden image', in other words spin-up an instance, configure it, install the software etc and then save it as an AMI (amazon machine image). Then tell the autoscaling group to use that AMI each time an instance starts - it will be pre-configured when it starts.
Put a script on the instance that tells the instance how to configure itself when it starts up (in the user data). SO basically each time an instance scales up, it runs the script and does all the steps it needs to to configure itself.
As for you data, best practice would be to store any data you want to keep in a database or object store that is not on the instance - so something like RDS, DynamoDB or even S3 objects.
You could also use AWS EFS, store there your data/scripts that the EC2 Instances will be sharing, and automatically mount it every time a new EC2 Instance is created via /etc/fstab.
Once you have configured the EFS to be mounted on the EC2 Instance (/etc/fstab), you should create a new AMI, and use this new AMI to create a new Launch Configuration and AutoScaling Group, so that the new Instances automatically mount your EFS and are able to consume that shared data.
https://aws.amazon.com/efs/faq/
Q. What use cases is Amazon EFS intended for?
Amazon EFS is designed to provide performance for a broad spectrum of
workloads and applications, including Big Data and analytics, media
processing workflows, content management, web serving, and home
directories.
Q. When should I use Amazon EFS vs. Amazon Simple Storage Service (S3)
vs. Amazon Elastic Block Store (EBS)?
Amazon Web Services (AWS) offers cloud storage services to support a
wide range of storage workloads.
Amazon EFS is a file storage service for use with Amazon EC2. Amazon
EFS provides a file system interface, file system access semantics
(such as strong consistency and file locking), and
concurrently-accessible storage for up to thousands of Amazon EC2
instances. Amazon EBS is a block level storage service for use with
Amazon EC2. Amazon EBS can deliver performance for workloads that
require the lowest-latency access to data from a single EC2 instance.
Amazon S3 is an object storage service. Amazon S3 makes data available
through an Internet API that can be accessed anywhere.
https://docs.aws.amazon.com/efs/latest/ug/mount-fs-auto-mount-onreboot.html
You can use the file fstab to automatically mount your Amazon EFS file
system whenever the Amazon EC2 instance it is mounted on reboots.
There are two ways to set up automatic mounting. You can update the
/etc/fstab file in your EC2 instance after you connect to the instance
for the first time, or you can configure automatic mounting of your
EFS file system when you create your EC2 instance.
I recommend using a shared data container if it is data that is updated and the updated data is needed by all instances that might be spinning up.
If it is database data or you could store the needed data in a database I would consider using an RDS.
If it is static data only used to configure the instances like dumps or configuration files which are not updated by running instances then I would recommend pulling them from CloudFlare or S3 of iT is not possible to pull them from a repository.
Good luck
I am new to cloud environment. I do understand the definition and storage types EBS and S3. I wanted to understand the application of EBS as compared to S3.
I do understand EBS looks like a device for heavy though put operations. I cannot find any application where this can be used in comparison to S3. I could think of putting server logs on EBS on magnetic storage, as one EBS can be attached to one instance.
S3 you can use the scaling property to add some heavy data and expand in real time. We can deploy our slef managed dbs on this service.
Please correct me if I am wrong. Please help me understand what is best suited for what and application of them in comparison with one another.
As you stated, they are primarily different types of storage:
Amazon Elastic Block Store (EBS) is a persistent disk-storage service, which provides storage volumes to a virtual machine (similar to VMDK files in VMWare)
Amazon Simple Storage Service (S3) is an object store system that stores files as objects and optionally makes them available across the Internet.
So, how do people choose which to use? It's quite simple... If they need a volume mounted on an Amazon EC2 instance, they need to use Amazon EBS. It gives them a C:, D: drive, etc in Windows and a mountable volume in Linux. Computers traditionally expect to have locally-attached disk storage. Put simply: If the operating system or an application running on an Amazon EC2 instance wants to store data locally, it will use EBS.
EBS Volumes are actually stored on two physical devices in case of failure, but an EBS volume appears as a single volume. The volume size must be selected when the volume is created. The volume exists in a single Availability Zone and can only be attached to EC2 instances in the same Availability Zone. EBS Volumes persist even when the attached EC2 instance is Stopped; when the instance is Started again, the disk remains attached and all data has been presrved.
Amazon S3, however, is something quite different. It is a storage service that allows files to be uploaded/downloaded (PutObject, GetObject) and files are replicated across at least three data centers. Files can optionally be accessed via the Internet via HTTP/HTTPS without requiring a web server. There are no limits on the amount of data that can be stored. Access can be granted per-object, per-bucket via a Bucket Policy, or via IAM Users and Groups.
Amazon S3 is a good option when data needs to be shared (both locally and across the Internet), retained for long periods, backed-up (or even for storing backups) and made accessible to other systems. However, applications need to specifically coded to use Amazon S3 and many traditional application expect to store data on a local drive rather than on a separate storage service.
While Amazon S3 has many benefits, there are still situations where Amazon EBS is a better storage choice:
When using applications that expect to store data locally
For storing temporary files
When applications want to partially update files, because the smallest storage unit in S3 is a file and updating a part of a file requires re-uploading the whole file
For very High-IO situations, such as databases (EBS Provisioned IOPS can provide volumes up to 20,000 IOPS)
For creating volume snapshots as backups
For creating Amazon Machine Images (AMIs) that can be used to boot EC2 instances
Bottom line: They are primarily different types of storage and each have their own usage sweet-spot, just like a Database is a good form of storage depending upon the situation.
How can i attach persistent storage on Elastic Beanstalk ?
I know i need to have a .config file where i set the parameters of the environment to run every time an instance is created.
My goal is to have a volume, let's say 100GB, that even if the instances got deleted/terminated, i have this volume with persistent data where all instances can access to read from.
I could use S3 to store this data, but it would require changes to the application, and latency could be a problem.
This way i could access the filesystem like any common server.
AWS now offer a solution called Elastic File System (Amazon EFS) that lets multiple instances access a shared file store.
If your desire is to have a central data repository that all EC2 instances can access, then Amazon S3 would be your best option.
Normal disk volumes are provided via Elastic Block Store (EBS). EBS volumes can only be mounted to one EC2 instance at a time. Therefore, to share data that is contained on an EBS volume, you will need to use normal network sharing methods to mount network volumes.
However, if your goal is to provide shared access without one specific instance sharing a volume to other instances, then it is better to use S3 because it is accessible from all instances. It would likely be worth the effort of modifying your application to take advantage of S3.
I am facing an architecture-related problem:
I have created a new environment in ElasticBeanstalk and pushed my app there. All good so far. I have set it to auto scale up/down.
My app depends on filesystem storage (it creates files and then serves them to users). I am using an EBS volume (5gb large) to create the files and then push them to S3 and delete them from EBS. The reason I'm using EBS is because of ephemeral filesystem in EC2 instances.
When AWS scales up new instances don't have the EBS volume attached because EBS can be attached to one instance at a time.
When it scales down, it shuts down the instance that had the EBS volume attached, which totally messes things up.
I have added to /etc/fstab a special line that will automatically mount the EBS volume to /data but that only applies for the instance I add the file to /etc/fstab. I guess the solution here would be to create a customized AMI image with that special line. But again, EBS can't be attached to more than one instance at a time, so it seems like a dead end.
What am I thinking wrong? What would be a possible solution or the proper way of doing it?
For some reason, I believe that using S3 is not the right way of doing it.
S3 is a fine way to do it: your application creates the file, uploads to S3, removes the file from the local filesystem, and hands a URL to access the file back to the client. Totally reasonable. Why you can't use ephemeral storage for this. Instance store-backed instances have additional storage available, mounted to /mnt by default. Why can't the application create the file there? If the files don't need to be persisted between instance start/stop/reboot then there's no great reason to use EBS (unless you want faster boot times for your autoscale instances I suppose).
I have an ec2 instance that is hosting a CentOS AMI image and the root device is EBS , however it is not EBS optimized.
I have installed a few packages on it now I want to stop and start it again , Amazon documentation says that the EBS data would be available but the instance store data would be lost.
How do I know where(EBS or Instance store) my packages are stored ? I see that package files are in /opr /var /etc directories .
Will I loose my installed packages if I stop and start the Amazon ec2 instance ?
Thanks.
When you create an EBS backed instance (with ephemeral or instance store storage, and it doesn't matter whether it's optimized or not optimized) you don't lose data in your /opt or /var or /etc directory or any of the system data. So you are safe to stop and then restart it. Keep in mind that your internal and public IP addresses change once you restart it.
The only data that you lose is if you have ephemeral volumes which are generally mounted volumes with devices like /dev/sdb, /dev/xvdb, /dev/xvdc, etc.
If you create an instance store "only" instance then you lose everything. However, you will be able to tell if your instance is this type by not having the option to "stop" it. Meaning you can only terminate it. These are the first type of instances that EC2 offered when they started and maybe up until 3-4 years ago were the only ones, so they are not used that much AFAIK unless you need an ephemeral volume as your root volume.
[Edit]
This is what it's supposed to look like for an EBS backed instance (non-optimized):
You will not lose your data if the instance is setup as EBS.
EBS optimised is another option which adds additional IOPS, useful for busy database applications, etc.