

New Amazon EC2 Feature: Boot from Elastic Block Store - jeffbarr
http://aws.typepad.com/aws/2009/12/new-amazon-ec2-feature-boot-from-elastic-block-store.html

======
nethergoat
This is tremendously useful and lowers the barrier to entry for new adopters.
Unfortunately, it's also a temptation to make poor design decisions.

One of the key benefits of EC2 and other cloud offerings is that, in a
properly automated environment, it is faster and easier to replace a faulty
node than to troubleshoot it. The same is true for upgrades - simply boot a
new instance from an updated AMI or Chef/Puppet/Cfengine/RightScale config and
point traffic at the new server. Minimal wheelspin, minimal downtime.

Those who use this new feature to take a, for lack of a better term, "server-
hugger" approach to cloud computing will miss out on this. Though it may
reduce their cloud onboarding time, it's inefficient in the long term and will
be an operational burden as the environment grows.

~~~
shykes
As cool as they are, I have 2 problems with Chef/Puppet/CFengine/Rightscripts.

1\. Long boot times. This gets worse as your recipes get beefier.

2\. Same script, different results. Running your recipe next year might not
yield the same result (e.g. if you don't specify a precise version of a
package to install).

~~~
mark_l_watson
I agree. I do use Chef and Capistrano to automate creating AMIs, but then I
like to just save the AMIs and boot from them. Also, creating a new AMI from
an old one is quick and easy.

------
spudlyo
This simplifies the old way I had to do this:

* Boot a 4MB busybox ami (very fast to load)

* init script loops trying to mount /dev/sdj

* Manually attach EBS root volume on /dev/sdj

* init script mounts /dev/sdj in /new-root

* pivot_root /new-root /old-root

* chroot /new-root /sbin/init

------
wouterinho
EBS costs $0.10 per GB and $0.10 per million I/O requests. Any ideas how much
it would cost per month to replace a "normal" AMI (which is free) with an EBS-
backed one like this?

~~~
fizx
You store a normal AMI on S3, which is $.15/GB. If you care about costs, you
should be doing all of your high IO tasks on the /mnt swap drive, so your IO
costs should be pretty low. It's probably a wash.

------
garyrichardson
This is great for people who have 1-2 machines running a website, but doesn't
really make any difference to people who are actually elastically scaling.

In fact, maintain state between stops/starts increases headaches for me. It's
a lot more tempting to incorporate manual voodoo instead of baking it into the
build process.

------
rubyrescue
after i just spent all day yesterday building and rebulding amis... this is
great.

i can see a lot of advantages in terms of boot time and having a much bigger
root but for us since boot time is negligable compared to puppet config time,
the biggest saving will come the next time we're doing the the whole
configure/test/ec2-bundle-vol/ec2-upload-bundle/ec2-register cycle, which is
so tedious.

------
mark_l_watson
I wish they had released this new feature a year ago - it would have saved me
a lot of effort setting up both customers and my EC2 backed applications.

I'll use this in the future, and I will convert my own permanent EC2 instance.
There is a bit of trickery that I had to learn to auto mount EBS volumes when
my AMIs start up - some Ruby scripting code I probably won't have to use
anymore.

~~~
robinpc
You mention conversion ... Anybody have any suggestions about how to convert
an S3-backed AMI to an EBS backed one (linux)? I'm wondering if there's some
grub trickery that needs to happen over and above the file copies to make
booting work?

