Is Db2 purescale supported on GCP?
Solution 1:
TL;DR: No. This feature requires function to share disks between Virtual Machines and that is not possible on GCP.
The confirmation for this can be found in IBM Db2 for SAP planning guide . In this guide, although it was meant for SAP deployments, they list the features for DB2 that are not supported on GCP:
SAP supports most IBM Db2 features on GCP. However, the following features are not currently supported:
High Availability and Disaster Recovery for Db2
Multi-partition Db2 databases
IBM Db2 pureScale feature
The reason for this is because in order to enable Db2 purescale you need to be able to share the same block storage with multiples VMS. In GCP the block storage has some limitations:
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For Persistent Disks (the disks used on GCE instances) you can't mount the same disk to two instances in RW mode (Read Write).
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You can use Cloud Storage buckets in your GCE instances, but most likely they will not fit the performance and latency requirements for DB2.
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You could use a service like NetApp Cloud Volumes Service since this will allow you to share volumes between VMS. But this creates an overhead since you will need to administer the storage.
Google Cloud created an article Deploying highly available IBM Db2 11.1 on Compute Engine with automatic client reroute and a network tiebreaker where they outline a way to deploy a DB2 cluster, but they didn't used DB2 pureScale due to the reasons I stated before.