Adding metadata capacity

Object metadata capacity can be consumed faster than object storage capacity in some cases, so you might need to add Storage Nodes to increase metadata capacity even if sufficient object storage capacity remains.

Space is reserved for object metadata and essential database operations on volume 0 of each Storage Node. Three copies of all object metadata are maintained at each site, evenly distributed across all Storage Nodes.

The grid's metadata capacity and object capacity can be consumed unevenly, depending on how you use the grid. For example, if you typically ingest large numbers of small objects or add large quantities of user metadata or tags to objects, your grid might run short on metadata capacity before overall storage capacity runs low.

You must add new Storage Nodes before object metadata exceeds 100% of the allowed metadata space. You can use the Grid Manager to monitor the metadata capacity of Storage Nodes and use charts to estimate how quickly metadata capacity is being consumed, as described in the instructions for monitoring and troubleshooting StorageGRID.

Guidelines for increasing metadata capacity

Before adding Storage Nodes to increase metadata capacity, review the following guidelines and limitations:
  • You can increase the grid's metadata capacity by adding one or more Storage Nodes to each site.
  • You must expand each site by the same number of Storage Nodes.
  • You cannot increase metadata capacity by adding storage volumes to existing Storage Nodes because metadata is stored only on volume 0.
  • The actual amount of space available for object metadata on any given Storage Node depends on the Metadata Reserved Space storage option, the amount of RAM for the node, and the size of volume 0.
  • StorageGRID keeps a copy of all object metadata at every site. For this reason, the metadata capacity for your system is limited by the metadata capacity of your smallest site.
  • After you add Storage Nodes, StorageGRID evenly distributes object metadata across all Storage Nodes at a site to increase the overall metadata capacity of the grid. No other user action is required.
  • Assuming sufficient object storage capacity is available, having more space available for object metadata increases the number of objects you can store in your StorageGRID system.