How many files can be saved into a Linux directory?

1.3 x 10²⁰

The theoretical limit on the number of files in a directory in the second extended file system for the Linux kernel is 1.3 x 10 raised to the power of 20. The second extended file system, or ext2, was designed by Remy Card to replace the extended file system. It was also the default file system in some Linux distributions, such as Debian and Red Hat Linux, before being supplanted by the more recent ext3, which is a journaling file system. The ext2 is still used in SD cards, SSDs and USB flash drives.