On Mon, Nov 05, 2018 at 08:31:46PM +0530, Pintu Agarwal wrote: > Hi, > > I have one requirement: > I wanted to have a swapfile (64MB to 256MB) on my system. > But I wanted the data to be compressed and stored on the disk in my swapfile. > [Similar to zram, but compressed data should be moved to disk, instead of RAM]. > > Note: I wanted to optimize RAM space, so performance is not important > right now for our requirement. > > So, what are the options available, to perform this in 4.x kernel version. > My Kernel: 4.9.x > Board: any - (arm64 mostly). > > As I know, following are the choices: > 1) ZRAM: But it compresses and store data in RAM itself > 2) frontswap + zswap : Didn't explore much on this, not sure if this > is helpful for our case. > 3) Manually creating swapfile: but how to compress it ? > 4) Any other options ? Loop device on any filesystem that can compress (such as btrfs)? The performance would suck, though -- besides the indirection of loop, btrfs compresses in blocks of 128KB while swap wants 4KB writes. Other similar option is qemu-nbd -- it can use compressed disk images and expose them to a (local) nbd client. Meow! -- ⢀⣴⠾⠻⢶⣦⠀ Have you heard of the Amber Road? For thousands of years, the ⣾⠁⢰⠒⠀⣿⡁ Romans and co valued amber, hauled through the Europe over the ⢿⡄⠘⠷⠚⠋⠀ mountains and along the Vistula, from Gdańsk. To where it came ⠈⠳⣄⠀⠀⠀⠀ together with silk (judging by today's amber stalls).
