Object storage requirements

General requirements are listed in General requirements.

Note the additional requirements for object storage:

  • To be able to deploy and work with object storage, run Virtuozzo Hybrid Infrastructure on physical servers.
  • Keep in mind that object storage uses more space than is occupied by all S3 objects. This happens because the S3 service also stores internal metadata about objects and their distribution across object servers. This metadata usually requires 0.5–11 percent of the space used by S3 data. Moreover, since version 4.6, Virtuozzo Hybrid Infrastructure provides backups for object metadata, which increase the metadata size by additional 0.5 percent. The backups have automatic retention and do not require any assistance from a system administrator. The metadata and backups use the same redundancy scheme that is configured for the S3 cluster.
  • Objects storage reserves additional RAM in case of a possible node failure. The RAM size of this additional reservation depends on the number of cluster nodes and is calculated by using the following formula:

    additional_RAM_reservation = minimum_RAM_reservation / number_of_S3_nodes - number_of_nodes_that_can_fail

    For example, the S3 cluster of five nodes may lose two nodes without data loss. In this case, the additional RAM size that will be reserved on each S3 node will be calculated as 16 GB / (5-2), that is 5.3 GB.

To better understand how to calculate the hardware configuration for object storage, consider the following examples with RAM and CPU reservations.

Example 1. If you have 3 nodes (1 system+metadata disk and 5 storage disks) and want to use 3 replicas redundancy mode with the host failure domain, refer to the table below for the calculations. Note that three nodes are used for the management node high availability, and each of them meets the requirements for the management node.

3 nodes for the S3 cluster
Service Management nodes
System 4.5 GB, 3.3 cores
Storage services

5 storage disks, 1 metadata on system disk (each takes 0.5 GB and 0.2 cores), that is 3 GB and 1.2 cores in total

S3 Minimum reservation 16 GB, 8 cores
Additional reservation 16 GB / (3-1), that is 8 GB
Service reservations 31.5 GB of RAM and 12.5 cores
Minimum hardware configuration 32 GB of RAM and 12 cores
Recommended hardware configuration 48 GB of RAM and 16 cores

Example 2. If you have 5 nodes (1 system+metadata disk, 1 SSD cache disk, 10 storage disks) and want to use them for the S3 cluster, refer to the table below for the calculations. Note that three nodes are used for the management node high availability, and each of them meets the requirements for the management node.

5 nodes for the S3 cluster
Service Management nodes (nodes 1-3) Secondary nodes (4-5)
System 4.5 GB, 3.3 cores 1.5 GB, 1.1 cores
Storage services 10 storage disks, 1 metadata on system disk, 1 cache disk (each takes 0.5 GB and 0.2 cores), that is 6 GB and 2.4 cores in total 10 storage disks, 1 metadata on system disk, 1 cache disk (each takes 0.5 GB and 0.2 cores), that is 6 GB and 2.4 cores in total
S3 Minimum reservation 16 GB, 8 cores 16 GB, 8 cores
Additional reservation 16 GB / (5-2), that is 5.3 GB 16 GB / (5-2), that is 5.3 GB
Service reservations 31.8 GB of RAM and 13.7 cores 28.8 GB of RAM and 11.5 cores
Minimum hardware configuration 32 GB of RAM and 14 cores 32 GB of RAM and 12 cores
Recommended hardware configuration 48 GB of RAM and 16 cores 48 GB of RAM and 16 cores