I want to save disk space. Is it possible to decompose an MXF Sequence in order to keep only the portions of footage used in the sequence on my hard disk? The footage was captured on P2 cards and Firestore.

Decompose is not what you want.  Select your sequence and right-click select consolodate.  Set your handles, then select "delete original media" and that should do it.

Remember that if you digitised anything that is not used in your sequence that you consolodate, this media will remain and you would need to manually delete that media as well.

Be warned, though...  make certain that you are not trashing anything used in other sequences as well.

Thanks Clive. I will try your advice.

Can I consolidate more than one sequence at a time?

Yes - just select the sequences and go through the same routine.