Reviewing the options and limitations of each type of expansion

Before performing an expansion, you must understand the options and limitations of each type of expansion.

Adding storage volumes to Storage Nodes

You can increase the overall storage capacity of your grid by adding additional storage volumes (LUNs) to existing non-appliance Storage Nodes. You cannot expand the storage capacity of an appliance Storage Node. The maximum storage available on each StorageGRID appliance Storage Node is fixed, based on the appliance model and original configuration.

When preparing to add storage volumes, be aware of the following limitations:
  • Each node can support a maximum of 16 storage volumes. If you need to add capacity beyond that, you must add new Storage Nodes.
  • You cannot add capacity to an existing storage volume.
  • You cannot add storage volumes to a Storage Node at the same time you are performing a system upgrade, recovery operation, or another expansion.
  • Before adding storage volumes, you must review the active information lifecycle management (ILM) policy and rules. In most cases, you must add storage volumes to more than one Storage Node to satisfy ILM requirements for replicated or erasure-coded copies.

See "Adding storage volumes to Storage Nodes" for instructions.

Adding grid nodes to existing sites

You can expand storage capacity and add redundancy to a StorageGRID system by adding new grid nodes to existing data center sites. In a single expansion, you can add one or more of the following types of nodes to one or more existing sites:
  • Non-primary Admin Nodes
  • Storage Nodes
  • Archive Nodes
  • Gateway Nodes

When preparing to add grid nodes, be aware of the following limitations:

Adding a data center site

You can expand your StorageGRID system by adding a new data center site.

When preparing to add a data center site, be aware of the following limitations:
  • You can only add one data center site per expansion operation.
  • You cannot add grid nodes to an existing data center site as part of the same expansion.
  • The new data center site must include at least three Storage Nodes.
  • Because your StorageGRID system remains operational during the expansion, you must review ILM rules before starting the expansion procedure. You must ensure that object copies are not stored to the new data center site until the expansion procedure is complete. See the information about ILM rules.
  • When you add a new site, a copy of the Cassandra database (used for object metadata) is saved to the Storage Nodes at the new site. For this reason, adding a new site does not increase the number of objects you can store in the grid. To increase the maximum number of objects you can store in your StorageGRID system, you must increase the number of Storage Nodes per site, which increases the amount of space available for object metadata.