1. A method for making a consistent checkpoint of at least one page comprising at least one data object in a computer system having at least one primary and at least one secondary storage, said primary storage having at least one page which comprises at least one data object on the said page, the computer system allowing at least one write operation to modify at least one data object of the page, and said page being written into said secondary storage during the checkpointing, wherein the method comprises steps of: beginning the process of checkpointing, including at least one page in the primary storage into a group of pages to be checkpointed, altering at least one data object of said page with at least one data write operation during checkpointing before the page has been checkpointed, marking said at least one data object resulting from said at least one data write operation as a pending data object, writing at least one of the data objects of said page into the secondary storage, and altering the said at least one pending data object.