SvSAN Frequently Asked Questions

This FAQ attempts to answer a wide variety of queries relating to StorMagic SvSAN and its deployment. Click on any of the questions in the list to be taken to the corresponding answer further down the page.

If you cannot find the answer to your question, you can contact the StorMagic team at

Looking for answers on SvSAN's Data Encryption feature? You'll find everything you need on the dedicated Data Encryption FAQ page.

Question Index

General questions

Licensing & support

VMware vSphere

Microsoft Hyper-V

General questions

What is SvSAN?

SvSAN is the virtual SAN solution which enables simple and affordable hyper-converged infrastructure without compromising on reliability and performance.

SvSAN is a software-defined storage solution designed to deliver hyperconverged compute and storage infrastructure with two or more low-cost servers. It is uniquely optimized for cost-effective, multi-site data management, enabling continuous, high-speed data access for business-critical applications.

Eliminate the need for physical SANs, remove the worry of downtime for business-critical applications and significantly lower IT operating and acquisition costs. SMEs and large organizations across 72 countries have already chosen SvSAN to modernize their IT infrastructure.

This robust software product is designed for the realities of poor network reliability often found in remote areas, and it delivers highly-available hyperconverged infrastructure, even when networks have long latencies and limited throughput.

Which hypervisors does SvSAN support?

SvSAN supports the industry leading hypervisors, VMware vSphere and Microsoft Hyper-V. It is installed as a Virtual Storage Appliance (VSA) requiring minimal server resources to provide the shared storage necessary to enable the advanced hypervisor features such as High-Availability/Failover Cluster, vMotion/Live Migration and VMware® Distributed Resource Scheduler (DRS)/Dynamic Optimization.

For full details on hypervisor version compatibility, please refer to the SvSAN data sheet.

How many hosts do I need to enable High Availability?

SvSAN can be deployed as a simple 2-node cluster, with the flexibility to meet changing capacity and performance needs. This is achieved by adding additional capacity to existing servers or by growing the SvSAN cluster, without impacting service availability.

How does SvSAN achieve VMware High Availability?

SvSAN mirrors data between VSAs/cluster nodes synchronously, ensuring that the data is stored in 2 places before being acknowledged as complete.

Each side of the mirror (plex) is active, which allows data to be accessed from any plex. In the event that one side of the mirror fails (server failure, storage failure, network failure) data can still be access from the surviving plex.

While one side of a mirror is offline, changes to the surviving side are recorded on the meta-data journal. Upon recovery, the journal is read to determine which data has changed, this is then copied to the recovered side of the mirror, along with any new data written, this is known as a “fast resynchronization”.

The metadata journal should be at least 20 GB in size, which is capable of handling a very large number of changes. If the meta-data journal wraps fails, the system simply reverts to doing a full mirror resynchronization.

How does SvSAN protect against drive failures?

SvSAN does not explicitly handle protection against drive failures. The server on which the VSA is running will be protecting against drive failures using hardware RAID.

In cases where there is no RAID, the data is protected by SvSAN with a mirrored copy of the data on another SvSAN node.

How does SvSAN protect against unexpected power loss events?

The VSA is designed to handle any unexpected power loss. On startup, the VSA perform checks to determine if it was was previously shut down in a graceful manner.

If the VSA was previously shutdown abnormally, checks are run to ensure all the configuration data is consistent and correct.

A VSA contains dual boot images, to protect against corruption. If the primary boot image becomes corrupted, the VSA can boot from the other image.

What is the maximum storage capacity of SvSAN?

SvSAN has been designed to be scalable as far as possible, in that most entities do not have hard limits, but rather are limited by available hardware resources.

The maximum capacity of a virtual disk is 128 Petabytes.

What is the scalability of SvSAN?

The minimum scaling unit to provide highly available shared storage is two nodes, where virtual disks are mirrored between nodes.

A third server is used to provide quorum to protect against split-brain scenarios, this is called the Neutral Storage Host (NSH). The NSH can be located onsite, or remotely over a WAN. If a third node cannot be used, SvSAN can operate in a 2-node configuration using the  “Stay up Isolation Policy”

Beyond two nodes, any number of nodes can be supported. It is possible to create as many mirrored, virtual disks as capacity allows, and each can be mirrored between any pair of nodes.

What are the virtual requirements for SvSAN?

Minimum recommended requirements for SvSAN are:

CPU 1 x Virtual CPU core

  • 2 GHz or higher reserved
Memory 1GB RAM1
  • 1 x 512MB Boot device, used to store the VSA boot image and configuration data
  • 1 x 20GB Journal Disk, used to store journaling metadata, log files, etc.

SvSAN supports any disk type including hard disks, solid state disks and NVMe Flash

Network 1 x 1Gbps Ethernet

  • Recommend that 2 NICs are used for resiliency
  • 10Gbps and 40Gbps Ethernet are supported
  • Jumbo frames supported

1 Additional memory required when caching is enabled.

What is the maximum amount of memory SvSAN can utilize?

SvSAN can support up to 32 GB of memory.

How much memory is required for caching?

The following table shows the recommended amount of memory that needs to be allocated to the VSA based upon the memory and SSD cache sizes:

SSD cache size
Up to 0GB2 Up to 250GB Up to 500GB Up to 1000GB Up to 1500GB Up to 2000GB
Memory cache required 0GB1 1GB 3GB 3GB 4GB 5GB 6GB
3GB 5GB 6GB 6GB 7GB 9GB 10GB
4GB 6GB 7GB 7GB 9GB 10GB 11GB
6GB 9GB 9GB 10GB 11GB 12GB 13GB
8GB 11GB 11GB 12GB 13GB 14GB 15GB
12GB 15GB 16GB 16GB 17GB 18GB 20GB
16GB 20GB 20GB 21GB 22GB 23GB 24GB
20GB 24GB 24GB 25GB 26GB 27GB 28GB
24GB 28GB 29GB 29GB 31GB 32GB -

1 Memory caching disabled
2 SSD caching disabled

For more information on SvSAN's caching abilities, click here.

What is the minimum network bandwidth for mirroring?

The minimum network bandwidth is 1Gbps Ethernet.

SvSAN supports 10Gbps and 40Gbps Ethernet, jumbo frames and network teaming to provide network performance improvements.

Will I get better performance, if I use multiple NICs?

Yes, SvSAN will take advantage of all network links the virtual server has configured. SvSAN can be configured to load balance and aggregate the bandwidth of all available network interfaces. These can be used for management, mirroring or iSCSI traffic.

Is it possible to have a dedicated NIC to handle mirror traffic?

Yes, two virtual switches need to be configured on the virtual servers. SvSAN, by default is installed and configured with two virtual network interfaces (vNICs). However, more network interfaces may be added.

In the event that all network interfaces used for mirror traffic are unavailable, the mirror traffic will redirect over any remaining management network interfaces.

Can I convert an un-mirrored target to a mirrored target?

Yes, an existing un-mirrored target can be converted into a mirrored target and visa-versa. Please refer to the SvSAN manual or contact our support team at for detailed steps.

Where can I find the VSA serial number?

The serial number and current host name are displayed at the start of the configuration wizard.

After the setup is completed, you can view the serial number from the console, the system tab of the WebGUI or the VSA view>System tab, within the StorMagic Plugin. e.g. https://VSAname.domainname/system/license/

Does SvSAN support stretch/metro cluster configurations?

Yes, SvSAN cluster nodes can be located in different locations. For example different sides of a building, across campus or in different cities.

Please contact our support team at for details on bandwidth and latency requirements.

Is it possible to perform out of family firmware upgrades?

Yes, it is possible to skip a single firmware revision for example from SvSAN 5.1 to SvSAN 5.3. The intermediate upgrade to SvSAN 5.2 is not required.

Please refer to the SvSAN release notes for supported and valid upgrade paths.

Licensing & support

Can I get an trial copy of SvSAN?

Yes, a free, fully functional evaluation of SvSAN is available to download, enabling organizations to trial and experience the features and benefits of SvSAN before purchasing. For more information and to download an evaluation copy, visit the StorMagic website at

During the trial period, evaluators will receive support and assistance with the first installation and a product demonstration.

How is SvSAN licensed?

SvSAN is sold as a perpetual license in pairs of license keys for the total addressable usable VSA storage capacity.

  • Available in 2TB, 6TB, 12TB and Unlimited usable storage capacities
  • 1 license required per server/cluster node
  • Pricing based on 2 node license bundle (single licenses available)
  • Two editions - Standard and Advanced

SvSAN license include the first year of maintenance. Additional maintenance years can be purchased in increments of 2 and 4 years, for 3 and 5 year maintenance terms.

To discuss your maintenance requirements and obtain a quote contact our sales team at

What features are in the Standard and Advanced Editions?

SvSAN is available in two Editions – Standard and Advanced.

  • Standard Edition: Rich set of features for software-defined storage.
  • Advanced Edition: Adds key features for additional performance, flexibility and efficiency.

The following table provides an overview of the features in each edition:

Feature Standard Edition Advanced Edition
Synchronous mirroring/high availability X X
Stretched/metro cluster support X X
Volume migration X X
VSA restore1 X X
VMware vSphere Storage API (VAAI) support X X
Centralized management and monitoring X X
Remote shared quorum X X
I/O performance statistics X X
Multiple VSA GUI deployment and upgrade X X
PowerShell script generation X X
Write back caching (SSD) X
Predictive read ahead caching (SSD and memory) X
Data pinning X

1 VMware only

Is it possible to upgrade from Standard to Advanced Edition?

Yes, upgrading edition is available at any time.

Is it possible to increase the license capacity?

Yes, upgrading capacity is available at any time.

How do I get software updates and product support?

To get software updates and product support requires a valid maintenance and support contract.

StorMagic delivers 24/7, world-class support to ensure customers and partners can quickly and effectively troubleshoot any difficulties that may arise. Maintenance and support provides instant access to knowledge base articles, software updates including major and minor software updates (including bug fixes and new feature releases), as well the ability to log technical support requests.

Maintenance and support is available in two levels, Gold or Platinum.

What are the differences between the Gold and Platinum maintenance offerings?

Gold delivers daytime, weekday support, while Platinum offers 24/7 support 365 days a year. A summary of the maintenance levels is shown in the table below:

Gold Support Platinum Support
Hours of operation 9 hours a day, Monday - Friday 24 hours a day*, 7 days a week
Length of service 1, 3 or 5 years 1, 3 or 5 years
Product updates Yes Yes
Access method Email
Web Chat
Web Chat
Response method Email
Remote support / WebEx Yes Yes
Access to knowledgebase Yes Yes
Access to documentation Yes Yes
Disaster recovery assistance No Yes
Performance tuning No Yes
Upgrade assistance No Yes
SAN solution configuration Yes Yes
Maximum number of support administrators per contract 2 4
Number of support requests Unlimited Unlimited
Target response times
- Low 12 business hours 8 business hours
- Medium 8 business hours 4 business hours
- Critical 4 business hours 1 business hour
Business hours Monday - Friday Monday - Friday
Europe 8am - 8pm (GMT/BST) 8am - 8pm (GMT/BST)
North America 5am - 5pm (CST/CDT) 5am - 5pm (CST/CDT)

* Global 24x7 support for critical issues

For full details about maintenance and support, please refer to the policy.

To discuss your support requirements and obtain a quote contact our sales team at

VMware vSphere

Which versions of VMware vCenter does SvSAN support?

SvSAN supports VMware vSphere 5.5, 6.0 & 6.5

For full details on hypervisor version compatibility please refer to the SvSAN data sheet.

How does SvSAN integrate with vCenter?

SvSAN integration services are installed to either a Windows or Linux vCenter. The plugin provides virtual SAN management via wizard based deployment and ongoing administrative tasks directly within vCenter on premise or in a centralized location.

The StorMagic dashboard within the vCenter displays traffic light based health status for all VSAs managed by the vCenter and provides the capability to perform VSA firmware upgrades.

Where is the SvSAN console or GUI?

The SvSAN VSA VM presents a console available via the hypervisor tools to enable basic management tasks and ensure network connectivity.

VSAs are managed via the StorMagic vCenter plugin. Alongside this each VSA presents a web interface that can be used via any web browser using the VSA IP address or hostname.

What VMware components are required for SvSAN to run?

SvSAN requires VMware vSphere hypervisor and will run with or without vCenter. SvSAN can provide integrated vSphere management, if a vCenter server is available.

If a vCenter server is not available, SvSAN can be managed via a web interface and the hosts.

Can I install the SvSAN software and have an iSCSI network on a separate VLAN and Subnet from the Virtual Center server?

Yes, SvSAN fully supports all TCP/IP networking with architectures utilizing subnets or VLANS to segregate traffic types. Accessing the plugin while using VLANs requires the management interfaces to be configured between the vCenter and appliances. For example, you could have one VLAN containing a vCenter, Service Console and a SvSAN management interface, and another VLAN containing a VMKernel and another SvSAN interface providing a dedicated iSCSI VLAN.

Can I perform a non-disruptive upgrade of vCenter and SvSAN?

Yes, it is possible to perform a staggered, non-disruptive upgrade of both host and virtual appliance.

Does SvSAN support vCenter running in a virtual machine?

Running Virtual vCenter is supported dependent on configuration. Please contact support for more information on

Microsoft Hyper-V

Which versions of Windows Server and Hyper-V does SvSAN support?

SvSAN supports Windows Server and Hyper-V Server 2012, 2012 R2 and 2016.

For full details on hypervisor version compatibility please refer to the SvSAN data sheet.

Is there Microsoft System Center Operations Manager integration?

Yes, there is a StorMagic SCOM management pack that provides alerts and system status.