On Sun, Jun 7, 2020 at 11:18 PM John M. Harris Jr <johnmh(a)splentity.com> wrote:
On Sunday, June 7, 2020 11:51:38 AM MST Konstantin Kharlamov wrote:
> The third question touches the paragraph "Why not
zswap?". The only
> point it mentions is that swap-device is not encrypted. Fair enough,
> although I wonder why this never has been regarded as a problem before.
An important consideration is that zram is *also* not encrypted. If that's
enough to rule out zswap, it should be enough to rule out zram too.
/dev/zram0 isn't persistent.
> Let me emphasize that: 3GB of compressed RAM (ZSWAP + SWAP) is
not
> enough! The moral of this story is that you can't get away with only
> ZRAM without any disk SWAP. You need disk SWAP. And if you have disk
> SWAP, ZSWAP fits more nicely there as a compressing buffer before the
> data finally spills over to disk.
>
> 1:
https://fedoraproject.org/wiki/Changes/SwapOnZRAM#Why_not_zswap.3F
> 2:
>
https://github.com/Hi-Angel/scripts/blob/master/warn-on-low-memory.pl
Zswap sounds like an excellent idea to look into instead of zram. Not only
that, but it'd allow traditional entry in fstab to configure it, instead of
some systemd magic that nobody knows about.
zswap is configured by sysfs, same as zram.
It's a consideration, but I'm uncertain if it can happen for F33.
--
Chris Murphy