Disk types in Managed Service for OpenSearch

Managed Service for OpenSearch allows you to use network and local storage drives for database clusters. Network drives are based on network blocks, which are virtual disks in the Yandex Cloud infrastructure. Local disks are physically located on the cluster servers.

When creating a cluster, you can select the following disk types for data storage:

• Network HDDs (network-hdd): Most cost-effective option for clusters that do not require high read/write performance.

• Network SSDs (network-ssd): Balanced solution. Such disks are slower than local SSD storage, but, unlike local disks, they ensure data integrity if Yandex Cloud hardware fails.

• Non-replicated SSDs (network-ssd-nonreplicated): Network disks with enhanced performance achieved by eliminating redundancy.

  The storage size can only be increased in 93 GB increments.

• Ultra high-speed network SSDs with three replicas (network-ssd-io-m3): Network disks with the same performance characteristics as non-replicated ones. This disk type provides redundancy.

  Such disks can be increased in size only in 93 GB increments.

• Local SSDs (local-ssd): Disks with the best performance.

  The size of such a storage can be increased:

  • For Intel Cascade Lake: Only in 100 GB increments.
  • For Intel Ice Lake: In 368 GB increments only.

  For clusters with hosts residing in the ru-central1-d availability zone, local SSD storage is not available if using Intel Cascade Lake.

Selecting storage type when creating a clusterSelecting storage type when creating a cluster

The number of hosts with the DATA role you can create together with an OpenSearch cluster depends on the selected storage type:

• You can create a cluster only with three or more hosts when using the following disk types:

  • Local SSDs (local-ssd)
  • Non-replicated SSDs (network-ssd-nonreplicated)

  This cluster will be fault-tolerant.

  Local SSD storage has an effect on how much a cluster will cost: you pay for it even if it is stopped. For more information, refer to the pricing policy.

• You can add any number of hosts within the current quota when using the following disk types:

  • Network HDDs (network-hdd)
  • Network SSDs (network-ssd)
  • Ultra high-speed network SSDs with three replicas (network-ssd-io-m3)

For more information about limits on the number of hosts per cluster, see Quotas and limits.

To improve fault tolerance, you can set up index replication (for multi-host cluster configurations only).

Disk encryptionDisk encryption

When creating or restoring a cluster from a backup, you can encrypt the storage disk with a custom KMS key. To encrypt a disk of an already created cluster, disable encryption, or encrypt a disk with a different key, create a backup of the cluster and restore it with the new settings.

To create an encrypted disk, you need the kms.keys.user role or higher.

If you deactivate the key used to encrypt a disk, access to the data will be suspended until you reactivate the key.