Protected Domain Log Space is Low

This article applies to all JSDR software versions.

Issue

The following alert message may be displayed if adequate space is not available in the replication log volume.

Low replication log space warning.

Details of a Replication Log Volume

Each protected domain uses a single replication log for all the VMs belonging to it.
The replication log volume consists of multiple sections (described below):

Example of a replication log volume.

Replication Log Section

Keeps a record of data being replicated to the object store.
I/O coming into the DRVA is written to the object store.
If there is a network bottleneck the I/O will get written to the replication log.
(It acts as a temporary placeholder.)

Metadata Section

Contains metadata of the VMs including garbage collection (DB).

Free Space Section

When metadata becomes full, if there is available free space in the replication log volume, the management server will automatically re-assign some of the free space to metadata.

The “log space low” message can appear when the replication log section is full or >90% for a certain period of time. This message will stop appearing once the space is freed up.

Best Practices

The replication log section should be sized to 64GB per protected domain (regardless of the number of VMs being protected).
The number of vDisks protected should not exceed 500 per DRVA.

Example

If the replication log has been over provisioned, the replication log section can be resized to release free space on the replication log volume (RLV).