two questions about swap space
 

Is swap necessary for today's linux. I asked because it is not being used at least on my system. My second question is should swap be encrypted along with the root and home partition. Openbsd encrypts the swap space by default.

1. Swap is optional, not required. Your typical RAM usage is a good guideline for whether or not you'll benefit from swap.

2. I personally encrypt my swap, your mileage may vary.

Just curious but why do some people encrypt swap since it it rarely used? Is there stray data that we don't see or something?

Whether swap is used rarely or frequently is completely dependent on the user, the operating system, the hardware, and the task.

Since swap (if it is used) can contain sensitive data, it is only logical to encrypt it.

Thank you snowpine