Backup from IBM Rescue and Recovery

[GZheng12]

Today before installing some new software to my new T42, I used IBM Rescue and Recovery to save my system image in local HDD. I notice it takes up considerable big space. Since my HDD is only 40 G, I wonder next time if I use backup, it will overwrite my previous system image saved or take another 5 G space. Does anyone knows about this function?
Thanks.

[eriqesque]

It will do a suplemental back-up.