Cloud Storage

Cloud Storage Installation Requirements

Cloud Storage is designed for storing containers and large volumes of data. It provides replication, high availability, self-healing, and automatic container failover. This page outlines the specific infrastructure requirements for deploying Virtuozzo Application Management with Cloud Storage.

The main hardware requirements for infrastructure hosts and user hosts, which act as Cloud Storage clients, are described in the Local Storage guide. The Cloud Storage scenario adds a dedicated VStorage cluster with specific compute, disk, and networking requirements.

Virtuozzo Application Management cloud storage requirements
Cloud Storage installation profiles and recommended infrastructure
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Cloud Storage Cluster Roles

The basic element of Cloud Storage is a VStorage cluster. Its servers can perform three principal roles:

Metadata Service (MDS)Stores metadata about chunk servers, container chunks, virtual machine files, and the location of stored data.
Chunk Service (CS)Stores data on local disks as fixed-size chunks and provides access to it. A replication setting of 3:2 or higher is recommended.
Storage Client (CL)User nodes where VZ-based containers and virtual machines run while consuming storage from the Cloud Storage cluster.
Typical Cloud Storage cluster
Typical Virtuozzo Application Management deployment with a Cloud Storage cluster
Important: Erasure Coding is not recommended for production container data. It is intended for low-load use cases and static data.

General Requirements

In addition to infrastructure and user hosts, provide at least five bare-metal servers for the Cloud Storage cluster. Nine or more servers are recommended for improved performance. A separate internal network must be dedicated to Cloud Storage traffic and the CS and MDS roles.

Bare metal only: Cloud Storage servers must run on physical hardware. Virtual machines are not permitted because of the performance and stability impact.

Minimum CS and MDS Server Specifications

ResourceMinimum Requirement
CPU10 cores / 20 threads, 1.8 GHz or faster
Memory16 GB or more; dual-channel memory is strongly recommended
System and MDS Disk300 GB or more
Chunk Storage DisksAt least four separate SSD drives per CS+MDS server
Storage Network10 Gbit/s minimum; faster networking is recommended
  1. Run chunk services on at least five servers; nine or more are recommended.
  2. Run MDS services on approximately three or five servers.
  3. For clusters with up to 15 chunk-service servers, MDS may be combined with CS and user-node roles.
  4. For larger clusters, run MDS on dedicated servers.
  5. When MDS runs separately, use hardware specifications equivalent to CS servers.
  6. Add 1 GB of RAM to each MDS server for every 100 TB of total cluster storage.
For production platforms, keep CS and MDS roles separate from user nodes to avoid performance conflicts. Combining roles is suitable only for Sandbox or PoC installations.

Storage and Storage Device Requirements

Every Cloud Storage server requires 100–150 GB of reliable RAID1 storage, or an equivalent Linux LVM mirror, for the Virtuozzo 7 operating system.

Chunk-service servers export local directories as the storage backend. Each directory must use a separate ext4 file system that occupies exactly one disk and is not shared with other file systems.

  • Do not use RAID1, RAID5, RAID6, LVM, or dmraid for chunk-data file systems.
  • RAID controllers may expose individual disks as separate single-disk RAID0 arrays or JBOD devices.
  • Enable passthrough for every drive exported to the chunk service.
  • When passthrough is unavailable, configure a separate RAID0 for each individual drive.
  • Use a battery-protected RAID controller cache.

SSD Recommendations

  • Use server-grade SSDs.
  • Prefer SSDs with protection against data loss during power failure.
  • When low-end SSDs are used for chunk storage, add fast SSD or NVMe devices for journaling.
  • Dedicated journaling devices can improve overall cluster performance significantly.
  • The number and size of journal devices depend on the quantity and speed of the storage SSDs.
HDDs are not recommended for production platforms because of their limited IOPS performance.

Network Considerations

  • Use a separate network dedicated to Cloud Storage traffic.
  • Provide at least 10 Gbit/s network capacity.
  • Use 25 Gbit/s where possible for production systems.
  • Use non-blocking Ethernet switches.
  • Use network bonding to improve reliability.

Storage Sizing Guidelines

Cloud Storage keeps multiple replicas of each data chunk to provide high availability, redundancy, and balanced I/O. The replication level directly affects the amount of usable storage available from the raw disk capacity.

Use the official Virtuozzo Storage sizing guidance when calculating the total raw and usable capacity required for the cluster.

VM Usage

Virtual machines must not be used for Cloud Storage servers. They cause substantial performance loss and can reduce overall platform stability.

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