Don't have a Raspberry Pi so please excuse my ignorance but.
Am I right in understanding that the various Linux distributions are set up to page and swap to the SD card. ( After all by default, what else is there that one could page/swap to).
What is the long term prognosis for the SD card? Do they have a limit on the number of read/write cycles? Reminds me of a certain AIX system that was setup to do transaction logging to a DAT tape and the number of read/writes exceeded the recommended maximum within a month. ( Needless to say it was changed to disk logging.)
How much do SD cards vary in their performance.