So first, my machine is a ResMed S9 Autoset and I have a 1 gig card in it.
I was looking back in the data and I noticed that going back to February 8th, data for Flow Rate and Mask Pressure are included BUT... on the 7th, this data is not present (other data is, but not FL and MP). What's going on here?
The only explanation I can think of is that ResMed is using the file as a circular buffer and they are only keeping X number of days of data for the more storage intense metrics but come on... even for the MOST data intensive metrics on these things, the amount of data generated is trivial. They're only using 23 megabytes for a 1 gig card. Looking at the file structure I do see that the largest .edf files which are tagged with a _BRP suffix are only present going back 7 days.