Martin,
Enis,
Thank you for the help. So, assume I start up a new instance and specify 1 master with 100 GB and 5 slave nodes, several EBS volumes will be created. Now when I finish working in galaxy. I should first terminate the instance from the cloud console, and then terminate the master and slaves from the AWS console, right? Now, several EBS volumes are still up and can be deleted, except for one. To identify which volume has the data, I should look in my S3 bitbucket at the file persistent.txt, no? Is this file in a snapshot that is automatically created when I terminate an instance through cloud console?
Regarding the 1 TB limit, I am thinking that intermediate files can be moved out of the persistent files as they are no longer needed and saved somewhere else, so that galaxy is never working with more that 1 TB... I am unsure how tricky this will be but I suppose it is possible in principle? My conception of the workflow is limited, but I think we need to convert(groom) to sanger, map with tophat/bowtie, and then use cufflinks for comparing expression. I am trying to practice ahead of time to see what kind of files/sizes these steps generate and figure out how this can work on the cloud. Thanks again.
-----Original Message-----
From: Enis Afgan [mailto:eafgan@emory.edu]
Sent: Tue 11/23/2010 2:55 PM
To: Martin, David A.
Cc: galaxy-user@bx.psu.edu
Subject: Re: [galaxy-user] Galaxy on the Cloud/RNA-Seq
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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