Crosstalk noise, due to the finite dimension of the recording medium, is a fundamental limitation to storage capacity in volume holographic memory. We present a general theoretical analysis on the crosstalk noise in angle- and wavelength-multiplexed volume holographic memory systems. Results on storage capacity and its dependence on hologram separation and required signal-to-noise ratio are obtained and discussed. Crosstalk noise may also arise from the expansion or shrinkage of the storage medium during and after the hologram recording process. Its effects, including Bragg mismatch, pixel displacement and impulse broadening, are analyzed for Fourier-plane holographic memories. Complete compensation and optimization to eliminate or reduce these effects are presented and discussed.