System Requirements

Before setting up a Parallels Cloud Storage cluster, make sure you have all the necessary equipment at hand. You are also recommended to:

• Consult Using SSD Drives to learn how you can increase cluster performance by using solid-state drives for write journaling and data caching, and how many SSDs you may need depending on the number of HDDs in your cluster.
• Check Troubleshooting for common hardware issues and misconfigurations that may affect your cluster performance and lead to data inconsistency and corruption.

General

• Each service (be it MDS, CS or client) requires 1.5 GB of free space on root partition for logs. For example, to run 1 metadata server, 1 client, and 12 chunk servers on a host, you will need 21 GB of free space on the root partition.

Metadata Servers

• Parallels Cloud Server 6.0 or newer,
• 1 CPU core,
• 1 GB of free RAM per 100 TB of data in the cluster,
• 3 GB of free disk space per 100 TB of data in the cluster,
• 1 or more Ethernet adapters (1 Gbit/s or faster).

Note: It is recommended to place the MDS journal on SSD, either dedicated or shared with CS and client caches, or at least on a dedicated HDD which has no CS services on it.

Chunk Servers

• Parallels Cloud Server 6.0 or newer,
• 1/8 of a CPU core (e.g., 1 CPU core per 8 CS),
• 256 MB of free RAM,
• 100 GB or more of free disk space,
• 1 or more Ethernet adapters (1 Gbit/s or faster).

Notes:

1. On using local RAID with Parallels Cloud Storage, consult Exploring Possible Disk Drive Configurations .

2. Using a shared JBOD array across multiple nodes running CS services may introduce a single point of failure and make the cluster unavailable if all data replicas happen to be allocated and stored on the failed JBOD. For more information, see Configuring Failure Domains .

3. For large clusters (see Recommended Configuration ), it is critically important to configure proper failure domains to improve data availability. For more information, see Configuring Failure Domains .

4. Do not place chunk servers on disks already used in other I/O workloads, e.g., system or swap. Sharing disks between CS and other sources of I/O will result in severe performance loss and high I/O latencies.

Clients

• Parallels Cloud Server 6.0 or newer,
• 1 CPU core per 30,000 IOPS,
• 1 GB of RAM,
• 1 or more Ethernet adapters (1 Gbit/s or faster).

Note: For hard disk requirements and the recommended partitioning scheme for servers that run Parallels Cloud Server and participate in clusters, see the Hardware Compatibility section in the Parallels Cloud Server 6.0 Installation Guide .