On Tuesday 03 March 2009 7:25:17 am Tom Lane wrote:
> Adrian Klaver <aklaver@comcast.net> writes:
> > Nothing. I have created a Postgres instance on an EC2 virtual machine
> > with attached EBS(Elastic Block Storage). I only got as far as creating
> > in it and verifying it would run, no benchmarking. EC2 instances have
> > storage as part of the instance but it is temporary and goes away when
> > the instance is shut down. For a database you want EBS as it is a virtual
> > harddrive that persists. Should an EC2 instance go down, you just
> > reattach the EBS drive on reboot.
>
> ... I wonder whether you have any guarantees about database consistency
> in that situation? PG has some pretty strong requirements about fsync
> behavior etc, and I'd not want to take it on faith that a cloud
> environment will meet those requirements.
>
> Performance would be an interesting question too.
>
> regards, tom lane
The EBS starts out as a raw drive. You format it with the file system of your
choice and it gets mounted as a regular drive. From the point of view of the OS
it is a physical hard drive.
As to the cloud environment meeting the requirements I can only go with IBM on
this one- http://aws.amazon.com/solutions/featured-partners/ibm/
To quote:
"In the coming months, AWS will provide pay-as-you-go pricing for the Amazon EC2
running IBM service, enabling you to purchase these services by the hour. These
AMIs will enable you to utilize Amazon EC2 with many of the IBM platform
technologies you’re already familiar with in the cost-effective,
high-performance, reliable, and secure Amazon EC2 environment. The initial list
of IBM AMIs that Amazon EC2 will run include: IBM DB2, IBM Informix, IBM
WebSphere sMash, IBM Lotus Web Content Management, and IBM WebSphere Portal
Server."
Performance remains to be determined.
--
Adrian Klaver
aklaver@comcast.net