Dell ObjectScale 1.3 Administration Guide

General guidelines or limitations of the expansion service procedures

• Only one expansion operation may run at a time - either horizontal or vertical.
  WARNING:Parallel volume expansions of different object stores at the same time can cause node affinity issues. If you need to expand multiple object stores, begin and complete the expansion of one object store before beginning the expansion of the next object store.
• Expansions will not change the Erasure Coding (EC) scheme used by the object store.
  • For example, if the object store was deployed with 12+4 EC, it will remain so for the life of the object store, regardless of the number of nodes added later.
  • Increasing the number of nodes will provide better I/O performance and increase data fragment dispersal.

  When performing horizontal expansions, the new expansion node hardware must already be installed into the cluster and that it meets the necessary hardware and software requirements prior to initiating the horizontal expansion.

• During an object store expansion, the expansion will fail if certain pods are unable to start. In these cases, ObjectScale will create an alert that provides the specific details on which pod and what resource was not available. Use the details in the issue alert to resolve the underlying issue.
  CAUTION:Ensure that there are sufficient Storage Capacity, Memory and CPU resources available before you initiate an expansion procedure, otherwise the expansion may get stuck.

  Ensure there is no parallel workload occurring which may consume these resources while the expansion process is in progress. If a vertical expand procedure is initiated with fewer resources than it requires, there is a chance for a Data Unavailability until enough resources are added and expansion process completes.