I have an older SSD in my laptop full of static data, mostly FLAC and a few zip files, there's very few files less than 10MB and likewise writes are weekly rather than multiple per second. I'm reluctant to buy a new, legacy disk to get more space because I move the laptop round a lot and my experience with legacy disks and bicycles is that they are a bad combination.Looking at advantages of BTRFS different filesystems and HowToGeek I can't help thinking that ext2fs is likely to be the most space-efficient filesystem. It's not journalling, which is good for this application, and it's ok with large files. I don't think speed actually matters here, since the SSD is wildly faster than the music player needs.Is there a better filesystem for this than EXT2? Can I format an SSD as one of the read-only CDFS-style formats, and would that get me more usable space?
Space-efficient Linux filesystem for music disk?
filesystems;flac
Can I format an SSD as one of the read-only CDFS-style formats?  Yes. You can use mkisofs to write directly to your SSD, no existing filesystem or partition table necessary.mkisofs -o /dev/sdg /path2musicdir Then the block device (SSD) can be mounted the same as any other iso file   mount -o loop,ro /dev/sdg /mountpt NOTE: Files need to be named in an 8.3 format, unless you use the Rock Ridge, Joliet, or HFS/Unix extensions, which presumably will take a few additional bytes (fewer files for the sake of intelligent file names.)