How to migrate the storage of a running application?

Question

Data storage

There is an application that constantly interacts with a large number of small files in the server's local file system and several NFS-mounted folders from neighboring servers.
It will be cheaper to move to S3-like storage. It's happening at DigitalOcean, they have " Spaces " running on the AWS S3 protocol.
There is doubt about the speed of access: perhaps working with Spaces will be slower than direct access to files through NFS and local.
1. How to collect statistically reliable speed figures "how it will be when we move"?
And if the failure of the speed is not one and a half or more times slows down the work, then you need to move. And this is a time-consuming activity, for a couple of hours.
2. How to move without downtime?
PHP code works with files. The implementation of the interface is ready for both locally available files and for the S3 API. In addition, S3 can be mounted as a local mount.
I was thinking about for a control sample of files, say 5%, to include duplicate work with both local and S3 files and calculate the increase in time.

Answer 1

1. working with any s3 storage will be slower than connecting a disk, but everything needs to be looked at for what tasks you are doing this.
2. I would suggest looking at moving directly to AWS via AWS Storage Gateway .
3. On AWS you will find many tools for Transfer Acceleration to and from S3