Refine filesystem requirements (#2578)

Author: NataliaIvakina

modules/ROOT/pages/installation/requirements.adoc

@@ -107,9 +107,12 @@ For more information on Red Hat Enterprise Linux Life Cycle, refer to their link
 [[deployment-requirements-filesystem]]
 == Filesystem
 
-For proper ACID behavior, the filesystem must support flush (_fsync_, _fdatasync_).
-Since databases can put a high and consistent load on a storage system for a long time, it is recommended to use a file system that has good aging characteristics.
-The EXT4 and XFS are the **only** supported file systems.
+For proper ACID behavior, the filesystem must support flush operations such as _fsync_ and _fdatasync_.
+Since databases can place a high and consistent load on a storage system for long periods, it is recommended to use a filesystem with strong aging characteristics.
+
+On Linux systems, a POSIX-compliant filesystem is required.
+Network shares such as NFS do not meet this POSIX requirement.
+The only supported filesystems on Linux are EXT4 and XFS.
 
 See xref:performance/linux-file-system-tuning.adoc[Linux file system tuning] for details on how to configure the filesystem in Linux for optimal performance.