Linux. File systems

EXT4

   + Support for large file systems.

       Up to 1 exbibyte (EiB) volume size

       Up to 16 tebibytes (TiB) with 4 KiB block size

   + Journal checksums to minimize the chances of corruption.

   + Metadata checksums are supported since 2012.

   + Backward compatibility with Ext3 and Ext2 filesystems.

   + Faster file-system checking by skipping the unallocated block groups.

   + Transparent encryption is supported since 2015.

XFS

https://www.opennet.ru/base/sys/xfs_struct.txt.html

   + Supports larger file systems compared to ext4.

   + Supports metadata and quota journaling. It helps in faster recoveries after a system crash.

   + Integrated backup and restore functions. XFS has xfsdump and xfsrestore utilities, which can back up and restore contents.

   + Supports defragmentation and growth of file system while it's actively mounted.

   + Dynamically allocated inodes

   + Supports extended attributes and provide the ability to store additional name-value pairs per file.

   - XFS doesn't directly provide support for snapshots.

   - XFS doesn't support journal checksum that is used to check the correctness of the data.

   - XFS cannot disable journaling. The drawback is that flash disk lifetime will be reduced.

   - Metadata operations in XFS were slower. Therefore, deletions of large numbers of files will cause slower performance.

   - The volume of the XFS file system cannot be directly shrunk. It can only be shrunk indirectly through "Backup > Refill > Restore".

ZFS

About inodes limit

• All metadata is allocated dynamically, so no need exists to preallocate inodes or otherwise limit the scalability of the file system when it is first created. No limit exists on the number of file systems or the number of files that can be contained within a file system.
• I can not find any instructions on how to set the file quota (i.e. maximum number of files per filesystem/directory) or directory quota (maximum size that files in particular directory can consume) in ZFS. That is because it doesn't exist.
• ZFS does not have a fixed number of inodes, so there is no way to calculate a limit, per se. ZFS uses space for metadata, so as long as you have available space, you can use it for metadata.
• In ZFS, you will run out of inodes at the same time as you run out of space.