On Tue, Aug 29, 2017 at 09:57:11PM +0000, Chris Kalin wrote:
> It's also a decent idea to keep the total partition size under about 80%
> of the total drive size so that you get the same write performance no
> matter how full the partition gets. If partition size = drive size you'll
> start to see massive slowdowns as the drive gets closer to 100%.

On any non-broken setup, as long as you trim in some way, it's stricly worse
to do that compared to using the full disk size but not letting the
filesystem get above 80% full. Modern filesystems (ie, not FAT) suffer
greatly when they're full to the brim, you want to give them some free
space. That free space may be the same as the space the SSD uses for erased
blocks.

On a 99% full filesystem, they all suffer from fragmentation (except FAT but
FAT's best case natural fragmentation is worse than a sane's filesystem's
worst case), CoW filesystems may get premature ENOSPC, log-based ones will
need to do emergency garbage collection all the time, etc.

Meow!
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