For large files support, Cloud Files allows you to upload multiple file segments and a manifest file to map the segments together.

A few limitations:

• Files larger than 5 GB must first be segmened into smaller files.
• We recommend that you do not create file segments smaller than 100-200 MB.  
• Files larger than 10GB cannot be served from the CDN.

There are 2 options for uploading large files:

Automatically Segment & Upload:

The Swift Tool will segment your large file for you, create a manifest file, and upload them accordingly,  After the file has been uploaded this tool manages your file segments for you, deleting and updating segments as needed.  It will look like this: 

$ st -A https://auth.api.rackspacecloud.com/v1.0 -U glh -K 3a25c2dc74f24c3122407a26566093c8 upload -S 1048576 test_container largefile.iso
largefile.iso segment 1
largefile.iso segment 6
largefile.iso segment 9
largefile.iso segment 4
largefile.iso segment 5
largefile.iso segment 3
largefile.iso segment 7
largefile.iso segment 8
largefile.iso segment 2
largefile.iso segment 0
largefile.iso

Use the API with your Application:

You can use the Cloud Files API to incorporate large file support directly into your application. Here is a simple cURL example of how you can use the API:

# First, upload the segments 
curl -X PUT -H 'X-Auth-Token: <token>' \     http://<storage_url>/container/myobject/1 --data-binary '1' 
curl -X PUT -H 'X-Auth-Token: <token>' \     http://<storage_url>/container/myobject/2 --data-binary '2' 
curl -X PUT -H 'X-Auth-Token: <token>' \     http://<storage_url>/container/myobject/3 --data-binary '3'  
 
# Next, create the manifest file 
curl -X PUT -H 'X-Auth-Token: <token>' \     
-H 'X-Object-Manifest: container/myobject/' \     http://<storage_url>/container/myobject --data-binary ''
  
# Then you can download the segments as a single object 
curl -H 'X-Auth-Token: <token>' \     
http://<storage_url>/container/myobject

For more information:

Large Files Upload FAQ

Large Object Creation API Documentation