EBS root instances seem to not have any instance storage - is this correct or some odd bug?
I'm expecting to have /dev/sda to be the EBS backed volume, and then have the other instance storage devices there as /dev/sdb etc...
Is this an incorrect assumption?
It's not a bug. Unlike Ephemeral, EBS based instances don't give you any free storage.
You can however create a new EBS volume and attach it to your instance.
Cheers
Ray
EDIT: I believe I led you astray as this seems to have changed. You still cannot attach local disk to an existing running instance but this does seem to be possible at launch time.
See:
http://docs.amazonwebservices.com/AWSEC2/latest/UserGuide/index.html?Using_AddingDefaultLocalInstanceStorageToAMI.html
Taken from the above url, device mapping with an 80gb EBS root volume plus ephemeral storage.
https://ec2.amazonaws.com/
?Action=RegisterImage
&Name=MyImage
&KernelId=aki-f70657b2
&RamdiskId=ari-ff0d5cba
&RootDeviceName=/dev/sda1
&BlockDeviceMapping.1.DeviceName=/dev/sda1
&BlockDeviceMapping.1.Ebs.SnapshotId=snap-12345678
&BlockDeviceMapping.1.Ebs.VolumeSize=80
&BlockDeviceMapping.1.Ebs.DeleteOnTermination=false
&BlockDeviceMapping.2.DeviceName=/dev/sdc
&BlockDeviceMapping.2.VirtualName=ephemeral0
&...auth parameters...
Related
I have an m3 large. Although I can find the other EBS volumes associated with that instance in the Volumes Section.
But I am not able to find my 32GB SSD disk.
How can we take backup of this SSD?
It appears that you are referring to the Instance Store SSD volume that is provided as part of an m3.large Amazon EC2 instance.
Instance Store volumes are temporary (aka "ephemeral") and the content is lost when the instance is Stopped, Terminated or fails. Therefore, it is recommended only for temporary files and swap files. Be sure to copy off any data you wish to keep before the instance is Stopped.
Instance Store volumes are not the same as Elastic Block Store (EBS) volumes. While EBS provides a snapshot capability, this is not available for Instance Store volumes.
Instead, you must copy off any data you wish to keep via normal filesystem commands, or run traditional backup software. There is no snapshot-like capability available for Instance Store volumes.
I ran into some issues with my EC2 micro instance and had to terminate it and create a new one in its place. But it seems even though the old instance is no longer visible in the list, it is still using up some space on my disk. My df -h is listed below:
Filesystem Size Used Avail Use%
/dev/xvda1 7.8G 7.0G 719M 91% /
When I go to the EC22 console I see there are 3 volumes each 8gb in the list. One of them is attached (/dev/xvda) and this one is showing as "in-use". The other 2 are simply showing as "Available"
Is the terminated instance really using up my disk space? If yes, how to free it up?
I have just solved my problem by running this command:
sudo apt autoremove
and a lot of old packages are going to be removed, for instance many files like this linux-aws-headers-4.4.0-1028
Amazon Elastic Block Storage (EBS) is a service that provides virtual disks for use with Amazon EC2. It is network-attached storage that persists even when an EC2 instance is stopped or terminated.
When launching an Amazon EC2 instance, a boot volume is automatically attached to the instance. The contents of the boot volume is copied from an Amazon Machine Image (AMI), which can be chosen from a pre-populated list (including the ability to create your own AMI).
When an Amazon EC2 instance is Stopped, all EBS volumes remain attached to the instance. This allows the instance to be Started with the same configuration as when it was stopped.
When an Amazon EC2 instance is Terminated, EBS volumes might or might not be deleted, based upon the Delete on Termination setting of each volume:
By default, boot volumes are deleted when an instance is terminated. This is because the volume was originally just a copy of an AMI, so there is unlikely to be any important data on the volume. (Hint: Don't store data on a boot volume.)
Additional volumes default to "do not delete on termination", on the assumption that they contain data that should be retained. When the instance is terminated, these volumes will remain in an Available state, ready to be attached to another instance.
So, if you do not require any content on your remaining EBS volumes, simply delete them. In future, when launching instances, keep an eye on the Delete on Termination setting to make the clean-up process simpler.
Please note that the df -h command is only showing currently-attached volumes. It is not showing the volumes in Available state, since they are not visible to that instance. The concept of "Disk Space" typical refers to the space within an EBS volume, while "EBS Storage" refers to the volumes themselves. So, the 7GB of the volume that is used is related to that specific (boot) volume.
If you are running out of space on an EBS volume, see: Expanding the Storage Space of an EBS Volume on Linux. Expanding the volume involves:
Creating a snapshot
Creating a new (bigger) volume from the snapshot
Swapping the disks (requiring a Stop/Start if you are swapping a boot volume)
These 2 steps add an extra hard drive to your EC2 and format it for use:
Attach an extra hard drive (EBS: Elastic Block Storage) to an EC2
Format an EBS drive attached to an EC2
Here's pricing info. Free Tier includes 30GB. Afterward it's $1.25/month for 10GB on a General Purpose SSD (gp2).
To see how much space you are using/need:
Check your current disk use/available in Linux with df -h.
Check the size of a directory in Linux with du -sh [path].
I took an c1.xlarge instance in EC2(Ubuntu 12.04) which promised me 1690 Gigs of instance storage. But when I checked the instance, I could only find 450 Gigs of it. What am I overlooking and where?
For some instances, there is a special block device mapping necessary to mount every available instance storage space. Here is a link to a description on how to mount the extra space so that it also becomes available in your instance.
try cat /proc/partitions command and check if it is attached to your instance. There might be a case where EBS storage is not mounted on your instance however it would be available as attached storage. If you can see 1690 Gigs with above command, you have to mount remaining storage to your instance then only it would be available to your instance for usage and can be seen through df -kh command.
My instance swap file is disappearing when I start my instance.
I have an Ubuntu ec2 instance, and I follow the "Four-step Process to Add Swap File" instructions at https://help.ubuntu.com/community/SwapFaq:
sudo dd if=/dev/zero of=/mnt/512MiB.swap bs=1024 count=524288
sudo chmod 600 /mnt/512MiB.swap
sudo mkswap /mnt/512MiB.swap
sudo swapon /mnt/512MiB.swap
I then changed my /etc/fstab to include:
/mnt/512MiB.swap none swap sw 0 0
Since I am using a much bigger swap, this process takes some time, and I don't want to do it every time I start. I would rather pay for the storage. However, when I start my instance, the swap has disappeared. If I type 'top', the instance does not have a swap file in use.
What should I do?
While the Amazon EC2 instance you are using has EBS backed Root Device Storage, all EC2 instance types still have the EC2 instance storage (also known as an ephemeral store) available for use as well, and the smaller instance types (e.g. m1.small and c1.medium) have it attached and mounted at /mnt by default even (the larger ones not!).
The most important characteristic of this storage type to be aware of is, that the data on the instance store volumes persists only during the life of the associated Amazon EC2 instance.
This statement is nowadays a tiny bit misleading, insofar it applies to stopping an EBS backed instance as well (not rebooting though), i.e. the moment you stop that instance, the ephemeral volume mounted at /mnt is detached and deleted and all data stored there is lost, including your swap file of course; once you start the instance again, a new ephemeral volume will be attached and mounted at /mnt.
Solution
You can still use the EC2 instance storage (which is plentiful and free of charge) if you exactly know what you are doing (see section Background below), e.g. it is a perfect option for strictly temporary data or anything that can be recreated easily on demand, like a cache for example.
A swap file is matching this requirements as well of course, so you simply need to create a script with the commands outlined in your question and execute it on instance start to recreate the swap file. You should put a guard in place though, because the instance storage survives reboots, i.e. you neither need nor should recreate the swap file on reboots, just with real stop/start cycles.
Background
The instance storage used to be the only storage option when Amazon EC2 was first introduced, but the resulting severe limitations for everyday usage have fortunately been remedied with the Amazon Elastic Block Store (EBS) you are using as well accordingly. Eric Hammond has recently provided a great summary why You Should Use EBS Boot Instances on Amazon EC2, addressing this very topic:
If you are just getting started with Amazon EC2, then use EBS boot
instances and stop reading this article. Forget that you ever heard
about instance-store and accept my apology that I just mentioned it.
Once you are completely comfortable with using EBS boot instances on
EC2, you may (or may not) want to come back here and read why you made
a good decision.
I have an ebs-backed instance running on EC2. I'm using it to do some computationally intensive text processing on around 16Gb of data which is stored on sdb (i.e. the larger ebs volume associated with the instance).
I'd like to parallelized the processing by creating replicas of this instance, each with its own copy of the data. I can create an AMI from the instance but I need the image to include BOTH sda (the root ebs volume) AND ALSO sdb, which is the volume where all the data is. How can I make a replica of the whole package?
Creating an image in the AWS Management Console just copies sda (i.e. the root volume, which is too small to hold my data).
Is this even possible?
(PS: I don't even see the sdb volume in the AWS Management Console Elastic Block Store->Volumes panel)
Thanks!
I once needed this sort of setting where I had to setup a MySQL on a EBS backed machine with data store in a separate EBS Volume. The AMI had to be such that every time you instanciate it, it should have the data volume (with static data in it) attached. This is how I did:
Created an EBS backed instance from any existing image
Attached a EBS volume, performed mkfs, mounted on /database
Copied data to the volume, e.g. under /database/mysql
Created image of this setup from AMI web console.
Now, every time I launch this image, I see the volume with all the data is there. I just mount it on /database and things get going.
I am not sure, if this is helpful to you but your problem seemed to close to this.
Update after #NAD's comment
Yeah, AMI creation process excludes stuffs that are under
/sys
/proc
/dev
/media
/mnt
So, the trick is to not have stuffs that you want to bundle up with your AMI under these directories.
Also, if you have volume that you want to auto-mount at boot, register it in fstab