The objective of this article is to explain how the disk space is allocated for VPX provisioned on SDX appliance.

Instructions

Below is the logic applied when allocating the disk space for VPX provisioned on SDX appliance:
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Every VPX hosted on SDX appliance would be provisioned with primary disk of 20GB disk.
Secondary disk varies based on the memory(in MB) provided and the type of operation.

During provisioning:
RAM <= 4GB,  secondary disk size = 0 GB
RAM <= 10GB, secondary disk size = 42GB (20GB for 89xx or 91xx platform)
RAM > 10GB, secondary disk size = 82GB (40GB for or 89xx or 91xx platform)

During modification of memory of existing NS:
RAM <= 4GB,  secondary disk size = 20G GB
RAM <= 10GB, secondary disk size = 42GB (20GB for 89xx or 91xx platform)
RAM > 10GB, secondary disk size = 82GB (40GB for 89xx or 91xx platform)

For eg:

If a VPX is provisioned with 4096 MB RAM, total disk allotted would be 20GB (Primary disk: 20GB)

If the above VPX is modified to increase RAM to 6144 MB RAM, total disk allotted would be 62GB(Primary disk: 20GB, Secondary Disk: 42GB)

If the same VPX is modified to decrease RAM to 2048 MB RAM, total disk allotted would be 40GB(Primary disk: 20GB, Secondary Disk: 20GB)