Deployment requirements

This information details important hardware, software, and network requirements that are needed for deploying a generalized stretch cluster configuration for three availability zones.

Software requirements

IBM Storage Ceph 9.9.0

Hardware requirements

Use the following minimum hardware requirements before deploying a stretch cluster configuration.
Table 1. ceph-osd hardware requirements
Hardware criteria Minimum and recommended
Processor
  • 1 core minimum, 2 recommended.
  • 1 core per 200-500 MB/s throughput.
  • 1 core per 1000-3000 IOPS.
  • Results are before replication.
  • Results can vary across CPU and drive models and Ceph configuration (erasure coding, and compression).
  • ARM processors specifically can require more cores for performance.
  • SSD OSDs, especially NVMe, benefit from extra cores per OSD.
  • Actual performance depends on various factors, including drives, network, and client throughput and latency. Bench marking is recommended to assess performance accurately.
RAM
  • 4 GB or more per daemon is required (higher is recommended).
  • 2-4 GB can work, but performance might be slower.
  • Less than 2 GB is not recommended for optimal performance.
Network A single 1 Gb/s (bonded 10+ Gb/s recommended). The network latency between the two data sites should be less than 10ms.
Table 2. ceph-mon hardware requirements
Hardware criteria Minimum and recommended
Processor 2 cores minimum
Storage drives 100 GB per daemon. SSD is recommended.
Network A single 1 Gb/s (10+ Gb/s recommended)
Table 3. ceph-mds hardware requirements
Hardware criteria Minimum and recommended
Processor 2 cores minimum
RAM 2 GB per daemon (more for production)
Disk space 1 GB per daemon
Network A single 1 Gb/s (10+ Gb/s recommended)

Daemon placement

Table 4 lists the daemon placement details across various hosts and data centers.

Table 4. Daemon placement
Hostname Data center Services
host01 DC1 OSD+MON+MGR
host02 DC1 OSD+MON+MGR
host03 DC1 OSD+MDS+RGW
host04 DC2 OSD+MON+MGR
host05 DC2 OSD+MON+MGR
host06 DC2 OSD+MDS+RGW
host07 DC3 (Tiebreaker) MON

Network configuration requirements

Use the following network configuration requirements before deploying stretch cluster configuration.
Note: You can use different subnets for each of the data centers.
  • Have two separate networks, one public network and one cluster network.
  • The latencies between data centers that run the IBM Storage Ceph Object Storage Devices (OSDs) cannot exceed 10 ms RTT.
The following is an example of a basic network configuration:
  • DC1

    Ceph public/private network: 10.0.40.0/24

  • DC2

    Ceph public/private network: 10.0.40.0/24

  • Tiebreaker

    Ceph public/private network: 10.0.40.0/24

Cluster setup requirements

Ensure that the hostname is configured by using the bare or short hostname in all hosts. 
hostnamectl set-hostname SHORT_NAME
Important: The hostname command should only return the short hostname, when run on all nodes. If the FQDN is returned, the cluster configuration will not be successful.