In RH6.2, I was able to hibernate to disk by simply pushing the power off button (how it works in Win2K as well). However, after running the program to upgrade 6.2 to 7.1, the power button no longer suspends to disk. Clicking Fn-F4 still does a sleep to RAM, however.
Hibernate is BIOS dependant
I don't understand why BIOS dependence matters. Lots of other things are also BIOS dependent and they are expected to work. Shouldn't the latest Linux be as functional as win2k (which does hibernate correctly) or even as old versions of Linux (like 6.2, which also did hibernate correctly)?
APM suspend is entirely handled by the BIOS. Linux has no influence on it. Unfortunately some vendors test this suspend with only certain operating systems so if the suspend fails with Linux they don't notice. The suspend/resume is beyond our control if it does have problems. Some things help with certain boxes Switching from X to a text console before suspending The current 2.4.20 based errata kernel (as it doesnt use the APIC which throws some devices)