For the minimum system requirements for this release, see System requirements.
Yes. Either an Intel VT or AMD-V 64-bit x86-based system with one or more CPUs is required to run all supported guest operating systems.
For more information about host system requirements, see System requirements.
You need a 64-bit x86 processor-based system that supports either Intel VT or AMD-V hardware virtualization technology in the processor and system firmware.
For a complete list of XenServer certified systems, see the Hardware Compatibility List (HCL).
Yes. XenServer supports AMD Rapid Virtualization Indexing and Intel Extended Page Tables. Rapid Virtualization Indexing provides an implementation of nested tables technology used to further enhance the performance of the Xen hypervisor. Extended Page Tables provide an implementation of hardware assisted paging used to further enhance the performance of the Xen hypervisor.
XenServer runs on many notebook or desktop-class systems that conform to the minimum CPU requirements. However, XenServer only supports systems that have been certified and listed on the Hardware Compatibility List (HCL).
You can choose to run on unsupported systems for demonstration and testing purposes. However, some features, such as power management capabilities, do not work.
No. XenServer does not support using SD cards or USB cards for your XenServer installation.
We only support hardware that has been certified and listed on the Hardware Compatibility List (HCL).
For a complete list of XenServer supported limits, see Configuration Limits.
XenServer host systems can use up to 6 TB of physical memory.
XenServer supports up to 448 logical processors per host. The maximum number of logical processors supported differs by CPU.
For more information, see the Hardware Compatibility List (HCL).
The maximum number of virtual machines (VMs) supported to run on a XenServer host is 1000. For systems running more than 500 VMs, we recommend allocating at least 16 GB of RAM to dom0. For more information, see Change the amount of memory allocated to the control domain.
For any particular system, the number of VMs that can run concurrently and with acceptable performance depends on the available resources and the VM workload. XenServer automatically scales the amount of memory allocated to the control domain (dom0) based on the physical memory available.
If there are more than 50 VMs per host and the host physical memory is less than 48 GB, it might be advisable to override this setting. For more information, see Memory usage.
XenServer supports up to 16 physical NIC ports. These NICs can be bonded to create up to 8 logical network bonds. Each bond can include up to 4 NICs.
XenServer supports up to 32 vCPUs per VM. The number of vCPUs that can be supported varies by the guest operating system.
Consult your guest OS documentation to ensure that you do not exceed the supported limits.
XenServer supports up to 1.5 TB per guest. The amount of memory that can be supported varies by the guest operating system.
The maximum amount of physical memory addressable by your operating system varies. Setting the memory to a level greater than the operating system supported limit can lead to performance issues within your guest.
XenServer can allocate up to 255 VDIs including a virtual DVD-ROM device per VM.
The maximum number of VDIs supported depends on the guest operating system. Consult your guest OS documentation to ensure that you do not exceed the supported limits.
XenServer can allocate up to 7 virtual NICs per VM. The number of virtual NICs that can be supported varies by the guest operating system.
XenServer splits processing resources between vCPUs using a fair-share balancing algorithm. This algorithm ensures that all VMs get their share of the processing resources of the system.
XenServer doesn’t statically allocate physical processors to any specific VM. Instead, XenServer dynamically allocates, depending on load, any available logical processors to the VM. This dynamic allocation ensures that processor cycles are used efficiently because the VM can run wherever there is spare capacity.
XenServer uses a fair-share resource split for disk I/O resources between VMs. You can also provide a VM higher or lower priority access to disk I/O resources.
XenServer uses a fair share resource split for network I/O resources between the VMs. You can also control bandwidth-throttling limits per VM by using the Open vSwitch.
Guest operating systems
Yes. For more information, see Supported guest operating systems.
Yes. For more information, see Supported guest operating systems.
For a list of supported Windows guest operating systems, see Supported guest operating systems.
For a list of supported Linux guest operating systems, see Supported guest operating systems.
Can I run different versions of the supported operating systems or other unlisted operating systems?
We only support operating systems (OS) under OS vendor support. Although unsupported operating systems might continue to function, we might ask you to upgrade to a supported OS service pack before we can investigate any issues.
Applicable drivers might not be available for OS versions that are unsupported. Without the drivers, these OS versions do not function with optimized performance.
It’s often possible to install other distributions of Linux. However, XenServer can only support the operating systems listed in Supported guest operating systems. We might ask you to switch to a supported OS before issues we can investigate any issues.
XenServer doesn’t support any BSD-based guest operating systems for general-purpose virtualization deployments. However, FreeBSD VMs running on XenServer have been certified for use in specific Netscaler products.
The XenServer VM Tools are software packages for Windows and Linux guest operating systems. For Windows operating systems, the XenServer VM Tools for Windows include high-performance I/O drivers (PV drivers) and the Management Agent.
For Linux operating systems, the XenServer VM Tools for Linux include a Guest Agent that provides additional information about the VM to the XenServer host.
For more information, see XenServer VM Tools.
Yes. Docker is supported on Linux VMs that are hosted on XenServer.
No. You cannot run Docker containers on a Windows VM that is hosted on XenServer. This restriction is because XenServer does not support nested virtualization for Windows VMs.
In previous releases of XenServer and Citrix Hypervisor, a Container Management supplemental pack was available that enabled you to manage your Docker containers through XenCenter. This feature has been removed.
For more information, see XenCenter.
Yes. The XenCenter management console runs on a Windows operating system. For information about the system requirements, see System requirements
If you don’t want to run Windows, you can manage your XenServer hosts and pools by using the xe CLI or by using
xsconsole, a system configuration console.
Yes. You can set up XenCenter login requests to use Active Directory on all editions of XenServer.
For more information, see Manage users.
Yes. The Role Based Access Control feature combined with Active Directory authentication can restrict access for users in XenCenter.
For more information, see Manage users.
Yes. You can use a single XenCenter console to connect to multiple XenServer host systems.
Depending on the version of XenServer - yes. XenCenter is backwards-compatible with Citrix Hypervisor 8.0 and later versions. However, note that only Citrix Hypervisor 8.2 CU 1 is receiving full support.
Yes. You can connect to multiple resource pools from a single XenCenter console.
The Console tab in XenCenter provides access to the text-based and graphical consoles of VMs running Linux operating systems. Before you can connect with the graphical console of a Linux VM, install and configure a VNC server and an X display manager on the VM.
XenCenter also enables you to connect to Linux VMs over SSH by using the Open SSH Console option on the Console tab of the VM.
XenCenter provides access to the emulated graphics for a Windows VM. If XenCenter detects remote desktop capabilities on the VM, XenCenter provides a quick connect button to launch a built-in RDP client that connects to the VM. Or, you can connect directly to your guests by using external remote desktop software.
Command line interface (CLI)
For more information, see Command-line interface.
Yes. All editions of XenServer include a full command line interface (CLI) – known as
Yes. You can access the CLI by connecting a screen and keyboard directly to the host, or through a terminal emulator connected to the serial port of the host.
Yes. XenServer ships the xe CLI, which can be installed on Windows and 64-bit Linux machines to control XenServer remotely. You can also use XenCenter to access the console of the host from the Console tab.
Yes. You can log in using Active Directory on all editions of XenServer.
Yes. You can restrict user access on the xe CLI.
For more information, see Manage virtual machines.
Yes. You can export and import VMs using the industry-standard OVF format.
You can also convert VMs in batches using the XenServer Conversion Manager. Third-party tools are also available.
For more information, see Conversion Manager.
You can install a guest operating system by using:
- A CD in the CD-ROM drive of the host
- A virtual CD-ROM drive using technology such as DRAC
- Placing ISO images on to a shared network drive
- Network installation, if supported by the specific guest.
For more information, see Manage Virtual Machines.
Yes. Any VM created on XenServer can be cloned or converted into a VM template. A VM template can then be used to create more VMs.
Yes. VMs exported from older versions of XenServer can be imported to a newer version.
Yes. XenServer supports using snapshots in all editions. For more information, see VM Snapshots.
For more information, see Storage.
XenServer supports local storage such as SATA, SAS, and NVMe.
XenServer supports Fibre Channel, FCoE, Hardware-based iSCSI (HBA), iSCSI, NFS, and SMB storage repositories.
Yes. XenServer includes a built-in software-based iSCSI initiator (open-iSCSI).
XenServer requires NFSv3 or NFSv4 over TCP for remote storage use. XenServer currently does not support NFS over User Datagram Protocol (UDP).
Yes. Although we recommend using a dedicated NAS device with NFSv3 or NFSv4 with high-speed non-volatile caching to achieve acceptable levels of I/O performance.
Yes. XenServer supports Boot from SAN using Fibre Channel, FCoE, or iSCSI HBAs.
Yes. XenServer supports booting from BIOS and UEFI. However, UEFI Secure Boot is not supported for XenServer hosts.
For more information, see Network boot installations
Yes. We recommend using multipath for resilient storage connections.
No. XenServer doesn’t support software RAID.
No. XenServer doesn’t support proprietary RAID-like solutions, such as HostRAID or FakeRAID.
Yes. Thin cloning is available on local disks formatted as EXT3/EXT4, in addition to NFS and SMB storage repositories.
No. XenServer doesn’t support DRBD.
No. XenServer doesn’t support ATA over Ethernet-based storage.
For more information, see Networking
Yes. You can create a private network on a single host for resident VMs.
Yes. You can connect to or associate multiple physical networks that attach to different network interfaces on the physical host system.
Yes. VMs can connect to any network available to the host.
VMs hosted on XenServer can use any combination of IPv4 and IPv6 configured addresses.
However, XenServer doesn’t support the use of IPv6 in its Control Domain (dom0). You can’t use IPv6 for the host management network or the storage network. IPv4 must be available for the XenServer host to use.
Yes. XenServer supports assigning VM networks to specified VLANs.
By default, XenServer network interfaces are non-promiscuous and a VM can only see traffic for that VM and broadcast traffic.
This behaviour can be configured depending on the network stack that you are using.
If you are using the Linux bridge as the network stack, your virtual network interfaces can be configured for promiscuous mode. This mode enables you to see all traffic on a virtual switch. For more information about promiscuous mode configuration, see the following Knowledge Center articles:
- CTX116493 - How to Enable Promiscuous Mode on a Physical Network Card
- CTX121729 - How to Configure a Promiscuous Virtual Machine in XenServer
When you enable promiscuous mode on a virtual network interface, for a VM to make use of this configuration, you must also enable promiscuous mode within your VM.
If you are using the Open vSwitch (OVS) as your network stack, it acts as a Layer 2 switch. A VM only sees traffic for that VM. Also, the switch-port locking in XenServer enables increased levels of isolation and security. OVS cannot be configured in promiscuous mode.
Yes. XenServer supports physical network interface bonding for failover and link aggregation with optional LACP support. For more information, see Networking.
Three components contribute to the memory footprint of a XenServer host.
- The Xen hypervisor
- The control domain on the host (dom0)
- The XenServer Crash Kernel
The amount of memory required to run dom0 is adjusted automatically. By default, XenServer allocates 1 GiB plus 5% of the total physical memory to the control domain, up to an initial maximum of 8 GiB.
The amount of memory allocated to the Control Domain can be increased beyond the default amount.
In XenCenter, the Xen field in the Memory tab reports the memory used by the Control Domain, by the Xen hypervisor itself, and by the XenServer Crash Kernel. The amount of memory used by the hypervisor is larger for hosts with more memory.
For more information, see Memory usage
Yes. XenServer uses Dynamic Memory Control (DMC) to adjust automatically the memory of running VMs. These adjustments keep the amount of memory allocated to each VM between specified minimum and maximum memory values, guaranteeing performance and permitting greater VM density.
For more information, see VM memory.
For more information, see Hosts and resource pools.
A resource pool is a set of XenServer hosts managed as a unit. Typically, a resource pool shares some amount of networked storage to allow VMs to be rapidly migrated from one host to another within the pool.
No. A single host in the pool must be specified as the pool coordinator. The pool coordinator controls all administrative activities required on the pool. This design means that there is no external single point of failure. If the pool coordinator fails, other hosts in the pool continue to operate, and the resident VMs continue to run as normal. If the pool coordinator cannot come back online, XenServer promotes one of the other hosts in the pool to coordinator to regain control of the pool.
This process is automated with the High Availability feature. For more information, see High availability.
A copy of the configuration data is stored on every host in the resource pool. If the current pool coordinator fails, this data enables any host in the resource pool to become the new pool coordinator.
Shared remote storage and networking configurations can be made at the resource pool level. When a configuration is shared on the resource pool, the coordinator system automatically propagates configuration changes to all the member systems.
Yes. Any new host systems added to a resource pool automatically receive the same configurations for shared storage and network settings.
Yes. We recommend that the same CPU type is used throughout the pool (homogeneous resource pool). However, it is possible for hosts with different CPU types to join a pool (heterogeneous), provided the CPUs are from the same vendor.
For more information, see Hosts and resource pools.
For updated information about the support for feature masking for specific CPU types, see Hardware Compatibility List.
Live Migration (formerly XenMotion)
For more information, see Migrate VMs.
With live migration you can move running VMs when hosts share storage (in a pool).
Also, storage live migration allows migration between hosts that do not share storage. VMs can be migrated within or across pools.
For more information, see High availability.
Yes. If high availability is enabled, XenServer continually monitors the health of the hosts in a pool. If high availability detects that a host is impaired, the host is automatically shut down. This action allows for VMs to be restarted safely on an alternative healthy host.
No. If you want to use high availability, shared storage is required. This shared storage enables VMs to be relocated if a host fails. However, high availability allows VMs that are stored on local storage to be marked for automatic restart when the host recovers after a reboot.
Yes. High availability configuration allows you to define the order that VMs are started. This capability enables VMs that depend on one another to be sequenced automatically.
Yes. XenServer provides detailed monitoring of performance metrics. These metrics include CPU, memory, disk, network, C-state/P-state information, and storage. Where appropriate, these metrics are available on a per-host and a per-VM basis. Performance metrics are available directly (exposed as Round Robin Databases), or can be accessed and viewed graphically in XenCenter or other third-party applications. For more information, see Monitor and manage your deployment.
Data for the XenServer performance metrics are collected from various sources. These sources include the Xen hypervisor, Dom0, standard Linux interfaces, and standard Windows interfaces such as WMI.
Yes. XenCenter displays real-time performance metrics on the Performance tab for each running VM and for the XenServer host. You can customize the metrics that are displayed.
Yes. XenServer keeps performance metrics from the last year (with decreasing granularity). XenCenter provides a visualization of these metrics in real-time graphical displays.
For more information, see Install.
No. XenServer installs directly on bare-metal hardware, avoiding the complexity, overhead, and performance bottlenecks of an underlying operating system.
Yes. If you are running a supported version of XenServer you can upgrade to a newer version of XenServer instead of doing a fresh installation. For more information, see Upgrade.
If your existing version of Citrix Hypervisor or XenServer is no longer in support, you cannot upgrade or update directly to the latest version of XenServer.
- For XenServer 7.0, 6.5, and 6.2, you can first upgrade to XenServer 7.1 Cumulative Update 2 and then upgrade from XenServer 7.1 Cumulative Update 2 to Citrix Hypervisor 8.2 Cumulative Update 1.
- For other 6.x versions of XenServer, you cannot upgrade to the latest version and must create a fresh installation of Citrix Hypervisor 8.2 Cumulative Update 1.
- For out-of-support 7.x current releases of XenServer, you cannot upgrade to the latest version and must create a fresh installation of Citrix Hypervisor 8.2 Cumulative Update 1.
Any other upgrade path for these out-of-support versions is not supported.
XenServer requires a minimum of 46 GB of local storage on the physical host system.
Yes. You can install XenServer on the host system using PXE. You can also automatically install XenServer using PXE by creating a pre-configured answer file.
No. Xen is a Type 1 hypervisor that runs directly on the host hardware (“bare metal”). After the hypervisor loads, it starts the privileged management domain – the control domain (dom0), which contains a minimal Linux environment.
XenServer uses the device drivers available from the Linux kernel. As a result, XenServer runs on a wide variety of hardware and storage devices. However, we recommend that you use certified device drivers.
For more information, see the Hardware Compatibility List.
For information about XenServer licensing, see Licensing
Yes. For more information, visit Citrix Support and Services.
Yes. XenServer and Citrix provide Technical Support contracts that allow you to open support incidents on XenServer, in addition to Citrix products.
For more information, visit Citrix Support and Services.
No. You can buy a technical support contract from XenServer either at product point-of-sale or at another time.
Yes. There are several alternative channels for getting technical support for XenServer. You can also use Citrix Knowledge Center, visit our forums, or contract with authorized XenServer partners who offer technical support services.
No. XenServer doesn’t provide technical support for the open-source Xen project. For more information, visit http://www.xen.org/.
No. Raise any non-technical issues with XenServer through Citrix Customer Service. For example, issues to do with software maintenance, licensing, administrative support, and order confirmation.