No, it's more like swapping pages to disk when RAM is full, or like using RAM when the L2 cache is full.
Linux page cache exists to speed up access to the durable store which is the underlying block device (NVMe, SSD, HDD, etc).
The RAM-backed block device in question here is more like tmpfs, but with an ability to use the disk if, and only if, it overflows. There's no intention or need to store its whole contents on the durable "disk" device.
Hence you can do things entirely in RAM as long as your CI/CD job can fit all the data there, but if it can't fit, the job just gets slower instead of failing.
Comments
No, it's more like swapping pages to disk when RAM is full, or like using RAM when the L2 cache is full.
Linux page cache exists to speed up access to the durable store which is the underlying block device (NVMe, SSD, HDD, etc).
The RAM-backed block device in question here is more like tmpfs, but with an ability to use the disk if, and only if, it overflows. There's no intention or need to store its whole contents on the durable "disk" device.
Hence you can do things entirely in RAM as long as your CI/CD job can fit all the data there, but if it can't fit, the job just gets slower instead of failing.