If a user boots a system without swap, the system will still boot and Linux will dynamically allocate memory, and is very good at it.
Yes, this could cause the system to run slower (not using swap) and thrash, but it can still be done.
Quote:
Thrashing can occur when total virtual memory, both RAM and swap space, become nearly full. The system spends so much time paging blocks of memory between swap space and RAM and back that little time is left for real work. The typical symptoms of this are obvious: The system becomes slow or completely unresponsive, and the hard drive activity light is on almost constantly.
So the "absolute" answer "NO" is not really accurate.
It can be done and the system will work if swap is turned off, but your performance could dive and the system thrash.
Is it a good idea? Well, that depends on the constraints the user is working under, but if it is working well now, why do it?
I have ran many Linux servers over the years with zero swap and they work fine, but I like to have a lot of memory in servers.
There is nothing wrong with experimenting; but you need to be careful of course if the system is a production system with critical apps in real or near-real time.
It does not hurt (if the system is not critical to production) to turn swap off if you really need to reclaim the disk space and for some reason don't want to add more disk space.
Having said that, both memory and disk space is pretty cheap these days, so why torture yourself about all this?
Is this a mission critical production server that you do not want to bring down to add disk space or memory?
Why not add more memory and / or disk space?
Thanks.