It can be difficult to find the most appropriate filesystem for your embedded system's eMMC or SD card storage. You can benchmark your system with each of them, but it can be time consuming. In this talk, we will compare all the actively maintained block filesystems supported in the Linux kernel: ext2, ext4, xfs, btrfs, f2fs, squashfs and erofs. Each of them will be properly introduced, with its basic design principles and main features. We will then compare each filesystem in terms of kernel module size and load time, filesystem mount time (important for boot time), filesystem size, as well as read and write performance on a few simple scenarios. We will also look for the best compression algorithms for filesystems with compression options. Performance comparisons will be run both on a 32 bit ARM board and on a 64 bit ARM one, both using a fast SD card as storage device. Filesystem performance can really depend on the benchmark, on your storage and on your CPU, so no universal results should be expected. However, you will learn what the best solution is in specific hardware configurations and testcases. No AI will be used to prepare, write this presentation and answer your questions. Only a human brain with 20 years of experience with Embedded Linux.