When you configure the proxy, after copying the init file over from the source, adjust the memory settings to match what you have on the proxy server. It should use those settings.
If you are not looking to run incremental backups, you can also pick the option to use the File System iDA for the backup copy. Of course only full backup will be supported, but you would not need to have Oracle installed on the proxy for that to work, and if you use deduplication, your over all storage/media consumption should not be that bad.
One last option would be to use the block level (volume copy) option. This uses our new block level backup mechanism (Which also does not use RMAN) but it does allow for incremental as well as enable the ability to run synthetic full backup. This also enables the ability to perform instant clone from the block level backup (without the need for hardware snapshot)
All these options can be found in the documentation for Oracle/Intellisnap under advanced configuration:
Oracle IntelliSnap - Backup Copy
Configuring Proxy Clients for Backup Copy Operations
Let us know iff this helps.
Ernst F. Graeler
Applications and File Systems