How can I create a recovery partition in memory as an option when booting the PC so that I can check all partitions including the system one that typically loads Ubuntu. This way I can fsck for example the partition that is normally running Ubuntu but without having it running it at that moment.

The recovery partition would have access to some tools to check the disck, memory, etc.

Is this doable?

Just to clarify with the whole recovery partition, I would boot the PC and load the normal GRUB menu but it would have an additional option to load some kind of image that would load into memory and from there it would start the system (Everything running from memory). So I could for example, do a fsck on all hard drives and do other checking while taking the advantage of the increased speed of using the memory to host the recovery system (Without using the hard drives).