Metadata server and method for distributing metadata in units of directories using the same

A metadata server, comprising:

• a request reception unit for receiving a request for at least one of creation, deletion, and retrieval from a user file system;
• an inode acquisition unit for acquiring an inode corresponding to an identifier of a parent inode, which is included in the request;
• a request analysis unit for determining whether the request is in regard to a file or a directory;
• a metadata distribution unit for searching for a dentry corresponding to the request, creating a new inode or searching for or deleting an inode corresponding to the dentry when the request is in regard to a file, and processing the request using a secondary metadata server to which metadata are distributed in units of directories when the request is in regard to a directory;
• and
• a directory management unit for adding a new dentry to the parent inode or deleting the inode corresponding to the dentry from the parent inode based on a result of processing the request.

A metadata server, comprising:

• a block search unit for searching for a block corresponding to a user request using a block structure including a block index field, a lock field, a dirty field, a dirty start time field, and a block data field;
• a grouping unit for grouping all blocks to be flushed based on at least one of a maximum number of blocks to be included in each group and a distance between blocks;
• and
• a flushing unit for gradually flushing the grouped blocks.