A distributed object sharing system and a method thereof are provided. In a file server writing method for storing an object in a RAID (redundant array of inexpensive disks) apparatus having a plurality of storage apparatuses, the file server writing method includes: a first process of, when an object writing command for a specific object is generated during error recovery in an erroneous storage apparatus, checking a recovery state of the object with reference to recovery state information provided from a metadata server; a second process of, when the recovery of the object is completed, performing the object writing command on a normal storage apparatus and a recovery storage apparatus; a third process of, when the recovery of the object is proceeding, receiving the recovery state information from the metadata server again, checking the recovery state of the object again, and determining whether or not to perform the second process; a fourth process of, when the second process is determined not to performed, performing the object writing command on only the normal storage apparatus and receiving the recovery state information from the metadata server again; and a fifth process of checking the recovery state of the object with reference to the received recovery state information and, when the recovery of the object is completed, additionally performing the object writing command on the recovery storage apparatus. Accordingly, it is possible to prevent data loss and perform I/O command during error recovery.