Meta server: check replay directory consistency as early as possible in startup sequence, to detect possible error at the beginning of the checkpoint loading process in order to minimize the error detection time. Check the link count of the "last" log directory entry and declare error if the "last" entry's link count is not equal to 2. The later is need to replace misleading "log.<n+1> not found" error message in the case when the "last" entry was copied / restored with "cp" instead of "cp -a" or cpio/tar for example.