Bug#832010: Please enable LZ4 compression

[Yuri D'Elia]

On Thu, Jul 21 2016, Michael Biebl <biebl at debian.org> wrote:
>>> LZ4 is the default compression method according to upstream since systemd
>>> 229.
>
> What exactly do you mean by "default"?
> Afaics, the default is no compression at all.

For journal entries probably not, but for core files compression is on
by default.

> If we build against liblz4, what happens with existing journal files?

By reading briefly through the code, if both lz4 and xz are available,
both will be read but new entries will be compressed directly with lz4.

> What happens with existing journal files, if it turns out that the LZ4
> compression causes problems and we have to disable it again?

Cannot answer this, but if we turn it on it should likely stay on.
Likewise, we cannot remove XZ support for the same reason (reading old entries).