The observations below are made from anaconda git logs, and should be verified against the actual version of Anaconda shipped for F21
- Low memory installations work better using methods where squashfs.img doesn't need to be kept in memory, ie nfs,live image.
- zRAM swap for Anaconda
zRAM is a standard block device like tmpfs with one nice difference -- its content is compressed. One clever usage of such device is using it as a swap device which effectively means one can have compressed RAM. Some experiments show that by using zRAM as a swap device in the installation process anaconda can install to machines with lower amount of RAM (succeeded with 320 MB) and installations on low-RAM systems (< 1 GB) run faster due to usage of zRAM swap instead/together with the standard swap we create and use for package installation. Specific limits, numbers and way of implementation may be changed in the future, but this commit introduces the basic idea and straightforward approach. --vpodzimek
zram can be turned on and off with the inst.zram argument. It will be used automatically for systems with <2GB, and not used for systems with >2GB.