GCS_SERVER_PROCESSES specifies the number of background GCS server processes (LMSn and LMnn) to serve the inter-instance traffic among Oracle RAC instances.

Property Description

Parameter type


Default value

If 1 - 3 CPUS, then 1

If 4 - 15 CPUs, then 2

If 16 or more CPUs, then 2 + (CPUs / 32). If the result includes a fraction, then the fraction is disregarded. For example, if you had 20 CPUs, then 2 + (20 / 32) would equal 2 GCS processes.Foot 1

If CLUSTER_DATABASE is set to false, then 0

If Oracle ASM, then 1



Modifiable in a PDB


Range of values

0 if Oracle RAC is disabled (CLUSTER_DATABASE is set to false)

1 to 100 if Oracle RAC is enabled (CLUSTER_DATABASE is set to true)



Oracle RAC

Multiple instances can have different values.

Footnote 1

On certain operating systems, the RDBMS optimizes the default allocation of background GCS server processes based on the core to thread ratio of the CPU.

GCS server processes are only seen in an Oracle RAC environment.