- Notes, cautions, and warnings
- Preface
- Introducing metro node
- Metro node use cases
- Features in metro node
- Integrity and resiliency
- Software and upgrade
Logging volumes keep track of blocks written:
After the inter-cluster link or leg is restored, the metro node system uses the information in logging volumes to synchronize the mirrors by sending only changed blocks across the link.
Logging volumes also track changes during loss of a volume when that volume is one mirror in a distributed device.
The logging volumes on the continuing cluster experience high I/O during:
Incremental synchronization
When the network or cluster is restored, metro node reads the logging volume to determine what writes to synchronize to the reattached volume.
There is no I/O activity during normal operations.