On Tue, Nov 06, 2018 at 09:09:16AM -0500, Stefan Monnier wrote:
I was reading about swap recently and fell upon (like a sword) this
remark from 2005 from Andrew Morton:
Create the swapfile when the filesystem is young and empty, it'll be
nice and contiguous. Once created the kernel will never add or
remove blocks.
He's talking about swap *files*: space in file systems tends to fragment.
It's pretty unusal for a typical filesystem to be so fragmented these
days that a new swapfile would have issues, unless the filesystem is
really full. (All of the current major fs's use extent-based allocation
and will write a file in a single contiguous block if possible.) So
overall I'd consider this an issue of mostly historical interest.
