On 20/11/2020 20:37, Andy Burns wrote:
> Martin Gregorie wrote:
>
>> The Wikipedia article I referenced describes zram as a swap device
>
> I think it's just a ram disc with compression, not specifically for swap
>
>> and zswap as a cache front-ending the swap device, i.o.w. zswap can
>> deal with memory over-subscription by evicting pages to an external
>> swap device: zram can't do this because it IS the swap device.
>>
>> The Wikipedia article describes them as alternatives.
>
> Yep.
>
> My machine with the existing 5.9GB swap device and the new 4GB zram swap
> device, certainly thinks it's got a total 9.9GB swap space now.

The free command shows the sum of the sizes of all swap devices
configured, but with zram swap active it will only ever use the zram RAM
for swap, and not any other swap devices.

As Martin says, that the difference between zram and zswap. zswap will
store compressed pages in RAM, and when that's full start using whatever
other swap device you have.

---druck

--- SoupGate-Win32 v1.05