Is there any way of booting from SSD/USB/NVMe/eMMC to have a Linux OS, such as Ubuntu, plus applications, services and containers load entirely into partitions created in RAM such as DDR3 or DDR4. This should ideally allow for use of other partitions, on say SSD or HDD for file storage regardless of which OS loads, probably FAT32 or exFAT for cross-OS support.
This is because even large Linux distributions use just a few units or tens of gigabytes, and many users want to use the same hardware for lots of distributions, e.g. home entertainment, software development, gaming, media production, office productivity, where users could select their environment from say a boot-loader or different USB keys, and run that environment entirely in RAM where user files reside on SSDs or HDDs, and there is a shut-down process, manual procedure or automated syncing of files in RAM archiving back to the original hard-drive/USB, for the next boot.
For example, you could have a customised Steam-based OS for gaming, switching to a media-streaming OS for relaxation or parties, switching to a office productivity OS and then an Education OS, or Webserver OS, from either USB keys or SSD partitions or similar, sharing user folders among different volatile-to-non-volatile loads of differing OSs, archiving back to original drives or keys. A large cheap RAID array or single SSD could function to store files such as games, files, media, but utilising the RAM for core OS, application, library and code and services etc.
Load times would increase but the OS, applications, libraries, services and databases, containers, plus gaming and media production speeds could be improved utilising lots of RAM and cheap USB loaders/archives or SSD rather than having to fork out on the cost of a large SSD or NVMe drive to accommodate those needs, which would load faster but be less responsive than loading the OS and apps into RAM.
The ability to run entire drive in RAM is also important in server scenarios especially databases which are not entirely suited to SSDs and more suited to RAM in terms of seek times, read and write times, bandwidth and numbers of rewrites and failures. For example, run a Linux Server OS including a Docker container of databases, server, code, libraries etc on one or more RAM partitions, utilising other drives for user files. Also RAM swap/working folder areas would be useful in backup or media production scenarios also, to reduce the time of archiving.
Many users are content with current bus speeds, but in professional and server and gaming and customisation markets the ability to a couple a fast CPU/GPU to OS file/service elements loaded into RAM would be very advantageous.
The idea came from a few 3rd party Windows software solutions which can create mapped partitions on RAM, archiving bakc manual to origin drive folders, also the Hyperdrive from years ago which used a PCI card and DDR(2?) memory as a recognizable internal hard drive. The idea could be applied to Linux kernels, especially in the movement from HDD to SDD to PCIe, go one step further to reduce complexity and potentially increase security of running certain functions or the entire OS from RAM.
An additional option could be to have a tiny NAND flash boot load in network scenarios for servers not using any HD but massive RAM arrays for volatile only storage, using external storage for backups/snapshots and boot files, or perhaps a remote network boot to load the OS from the cloud into RAM, archiving to another cloud.
6Gb/s on SATA3 for user files such as media, plus 25Gb/s from PC4-25600 for OS/libraries/apps/containers etc. Power supplies in most modern grids are consistent enough in nearly all scenarios, where UPSs or standard drives could be used in less developed electricity grids, and mobile situations.