...Every day you look, that is. Today I was doing another Udemy video course and the video was showing the /sbin directory on a popular Linux distro. The usual suspects were there but I noticed, in the several versions of fsck, among stalwarts like fsck.ext2, fsck.ext3, fsck.nfs and so on, one for Minix, of all things, which is indeed still around. But I noticed something even more odd, that I wasn't sure was a mistake, or a smear on my screen: fsck.cramfs.
CramFS?! Is there a filesystem by that name? Surely that's some Intercal-type April Fool joke.
It's no joke. And don't call me Shirley.
The Compressed ROM File System is, like the name suggests, designed to take up very little space. It's often used for embedded systems (the whole thing) but also as an assist for bigger systems. It's really little. A file has to be smaller than 16MB and an entire file system is restricted to about 270MB. Although it's rather old and other schemes have taken over its uses in many Linux distributions, Debian continues to use it for initrd images and I understand that one or another version of SUSE uses it for install images. To maximize smallness (or perhaps stability) it's read-only, although it ships helpfully with some utilities like mkcramfs; that and others are contained in the Util-linux package.
Due to cramfs being obsolete by some arguments, many systems now use the also-weirdly-named squashfs. The tinyness theme continues. Ubuntu, Mint, Debian, Arch and many others currently use it for LiveCDs. Utilities for squashfs are available as well, and mksquashfs and unsquashfs have been ported up to Windows 8.1 at last notice.
And on top of everything else, both cramfs and squashfs, while they exist in a compressed form, do NOT, repeat, do NOT require uncompression to operate. Wow.
So if some admin tries to blindside you with insane Linux terms like these which in an alternate universe would probably not exist, thank me later. I would have lost a bet at the bar after a meeting due to tools named this way.
