Replacing on-disk swap files/partitions with ZRAM

[almereyda]

To continue a deviated discussion in an issue, I can only second @gmelikov's comment in

• Swap deadlock in 0.7.9 #7734 (comment)

on ZRAM. In fact it is the default on Fedora since two years.

• https://fedoraproject.org/wiki/Changes/SwapOnZRAM

They even increased the fraction of ZRAM to be used especially to improve systems running on small devices.

• https://fedoraproject.org/wiki/Changes/Scale_ZRAM_to_full_memory_size

  Increasing the size of the device is important for small devices. For devices with 1GB of RAM, sizing ZRAM to 1 GiB allows successful installation with Anaconda. In general, it is expected that having more compressed swap will make the device more functional after installation too. This increase is the most important for devices with small amounts of memory (< 1 GiB), but will be beneficial to systems with slightly larger systems (1–8 GiB).

That said, Ubuntu will have to find a new ways to deal with ZFS anyway, after the demise of Zsys. They have both options available, with SystemD appearing to be the more native one:

• ❔ zram-config
• ✔ systemd-zram-generator

Please consult your favourite search engine and the originating conversation about other options to deal with swap.

• https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html

  The zram module creates RAM-based block devices named /dev/zram ( = 0, 1, …). Pages written to these disks are compressed and stored in memory itself. These disks allow very fast I/O and compression provides good amounts of memory savings.

• https://linuxreviews.org/The_Benefits_Of_Having_A_Compressed_zram_Swap_Device_On_Linux

  More zram swap is apparently better on real hardware