tune2fs
-I Change the inode size used by the file system. This requires rewriting the inode table, so it
requires that the file system is checked for consistency first using e2fsck(8). This operation can
also take a while and the file system can be corrupted and data lost if it is interrupted while in the
middle of converting the file system.
用它非格盘调整过 ext4 的保留空间，看 man 说明也能改 inode 数量
动手前做好备份（
