In the GFS Shared File System, up to two nodes can share one file system simultaneously. Therefore, file system processing can continue even if the node (on which MDS manages file system meta-data) fails. For such operation, you must select two nodes on which MDS can operate and set these nodes as MDS nodes. From the MDS nodes, select the primary MDS node (on which the primary MDS usually operates), the secondary MDS node (on which the secondary MDS usually operates).
See
For details on the effects of MDS node settings, see "3.1 MDS Failure Recovery."
As previously described in "4.3.1 Effects of file system operation and system load," the following should be taken into consideration:
CPU and I/O loads accompanying updating of the meta-data of the file system that occur on the MDS node operates
CPU throughput, I/O throughput, memory capacity, and swap area
Note
When activating the secondary MDS, activation of the primary MDS may take the time for a while.
