Your approach for terminating a cluster and starting it back up when it's needed should continue to be fine for your purposes. That's the best and pretty much the only way to minimize the cost. 
The reason there are 45 EBS volumes created is because each time you start an instance, a root EBS volume from snapshot 'snap-f3a64f99' is created to serve as the root file system. When you terminate that particular instance, that EBS volume is no longer needed and can be deleted (in the next AMI we build, we will enable deletion of that volume automatically upon instance termination). In other words, feel free to delete all EBS volumes that were created from a snapshot; they can be and are recreated when needed. The only volume that should not be deleted is your data volume. The ID of this volume can be found in your cluster's bucket (cm-<HASH>) in your S3 account in file named persistent_data.txt
As a reference, don't attach/detach EBS volumes manually to running Galaxy Cloud instances because the application will lose track of them and not be able to recover. In addition, always click 'Terminate cluster' on the Galaxy Cloud main UI and wait for it to shutdown all of he services; then *terminate* the master instance from AWS console (don't *stop* the instance).

As far as uploading 200GB of data to a cloud instance and processing it there. In principle, it should work. However, there is a 1TB limit on EBS volumes imposed by Amazon. As a result, and considering the multiple transformation steps your data will have to go through within Galaxy, I am concerned that you will reach that 1TB limit. We will be working on expanding beyond that limit by composing a filesystem from multiple EBS volumes but that's not available yet.

Hope this helps; let us know if you have any more questions,
Enis

On Tue, Nov 23, 2010 at 3:17 PM, David Martin <dmarti@lsuhsc.edu> wrote:
Hello,

We are about to get about 200 GB of illumina reads(43 bp) from 20 samples, two groups of 10 animals.  We are hoping to use Galaxy on the Cloud to compare gene expression between the two groups.  First of all, do you think this is possible with the current state of Galaxy Cloud development?  Secondly, we are currently practicing with small drosophila datasets (4 sets of 2 GB each), and over the course of a few days of doing relatively little besides grooming and filtering the data, we had already been charged $60 by Amazon, which we thought was a bit inefficient.  What is the best way to proceed working from one day to the next?  Should one terminate the cluster at Cloud Console and then stop(pause) the cluster at the AWS console, and then restart the instance the next day?  Does one have to reattach all of the EBS volumes before restarting the cluster?  We were just terminating the instance and then bringing it back up and all the data was still there, ie it worked fine, but when we looked after a couple days there were 45 EBS volumes there -  much of it was surely redundant as our data wasn’t very large.   Perhaps we need to take a snapshot and reboot the instance from this? Thank you for any hints regarding this matter, this is all very new to me.  Let me know if you need clarification or more information.

David Martin
dmarti@lsuhsc.edu

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