Patent attributes
A system and method for detecting mirror inconsistencies in a distributed storage environment. Inconsistencies between mirrors may be detected by comparing session tags among individual storage devices. Each data write may include a tag and storage devices may calculate session tags from the write tags. Additionally, a storage device may keep a history including tags from recent writes. When a client sessions ends, a metadata server may compare the respective session tags from different storage devices to determine whether the mirrors are synchronized. If the session tags do not match, the metadata server may examine the metadata histories from the storage devices to determine a cause for the discrepancy in the session tags. If examining the session histories fails to reveal the discrepancy's source, a metadata server may request individual data block checksums from storage devices to attempt a re-synchronization of the mirrored storage devices.
