> On 2016-11-27 06:27, Jeffrey 'jf' Lim wrote: > For some time now, my opinion has been to not use any swap at all for > any of my systems. Maybe I'm extreme, but when my systems fail, I want > them to fail categorically so that I know that something is wrong (I'm > assuming that there's something similar to the OOM killer on Linux) > instead of "not fail but grind along slowly". Am I wrong to think this > way?
Well, maybe not extreme, but it certainly depends on the use case and needs. Linux is the only OS in the family that is using memory overcommitment by default. It means, that Linux is fairly optimistic when assigning memory to the process in a way, that is assumes that process won't actually need to address all of it while running. This, of course, is rather shortsighted and it ended up with developing OOM killer -- which is at current stage fair from ideal. (Though maybe recent changes will make it better [1]). UNIX systems are not lying to the processes they are running -- if they have memory, they will make it available and if not -- they won't. Simple. Long story short, removing swap will not make system "fail categorically" -- if the system in mind is Linux, you just need to adjust overcommitment settings -- it can be done in a way, that will make it behave like a normal UNIX systems out there in the wild [2]. Otherwise, swap is just part of the virtual memory -- while you may not necessary need it on your laptop, it can certainly prove useful when you run out of RAM on your production MySQL server. If you are more into Solaris-way of handling memory, this one [3] proved fairly handy on couple occasion. [1] - https://lwn.net/Articles/668126/#reaper [2] - https://www.kernel.org/doc/Documentation/sysctl/vm.txt [3] - https://www.princeton.edu/~unix/Solaris/troubleshoot/SolarisMemory.pdf Best - Filip ------------------------------------------- smartos-discuss Archives: https://www.listbox.com/member/archive/184463/=now RSS Feed: https://www.listbox.com/member/archive/rss/184463/25769125-55cfbc00 Modify Your Subscription: https://www.listbox.com/member/?member_id=25769125&id_secret=25769125-7688e9fb Powered by Listbox: http://www.listbox.com
