Comment 3 for bug 1566129

Seth Arnold (seth-arnold) wrote :

How much swap space the installer should allocate was discussed at the Athens sprint, June 2016.

Near as I can recall the outcome was:

- The installer should configure a 1 or 2 gigabyte swap _file_ on the filesystem.

The actual size didn't much matter -- so long as the kernel has some swap available, it can make better RAM scheduling decisions than without swap available. No one wants to run too far into swap, and root filesystems can be small so don't use too much of it.

Putting it in a file makes it easier to resize or remove later.

Putting it in a file also makes it easier to encrypt the swap, if FDE is being used.

Putting it in a file does make it less reliable than a partition but by and large it should mostly work well enough.

There was also discussion about putting the swap file in a directory and perhaps configuring something to just swapon and use all files in the directory, so users can just fallocate files in there as they want.

There was also discussion about using https://www.kernel.org/doc/Documentation/vm/zswap.txt but I don't think there was consensus about whether or not this should be used by default.

Thanks