Patent ID: 7849355

Claim:
A file server writing method of a file server for updating an object stored in a RAID (redundant array of inexpensive disks) apparatus having a plurality of storage apparatuses, which include a normal storage apparatus storing the object and a recovery storage apparatus, using a metadata server, the file server writing method comprising: upon receiving an object writing command to update the object, checking whether the RAID apparatus is in an error mode; writing the object to the normal storage apparatus if the RAID apparatus is not in the error mode; and if the RAID apparatus is in the error mode; obtaining a recovery state information from the metadata server, and checking a recovery state of the object contained in the recovery state information to determine whether the recovery of the object is completed; if the recovery of the object is completed, performing the object writing command on the normal storage apparatus and the recovery storage apparatus; and if the recovery of the object is proceeding: receiving the recovery state information from the metadata server again, and checking the recovery state of the object again to determine whether or not the recovery of the object is completed and the object can be written to the normal storage apparatus; if the recovery of the object is completed, performing the object writing command on the normal storage apparatus and the recovery storage apparatus; and if the recovery of the object is not completed, performing the object writing command on only the normal storage apparatus, and repeatedly receiving the recovery state information from the metadata server again and checking the recovery state of the object in the received recovery state information, and, if the recovery of the object is completed, additionally performing the object writing command on the recovery storage apparatus.