XenServer 5.6 was announced a couple of weeks ago at Citrix Synergy, and this morning (Eastern US time) we posted it for download on citrix.com.  If you are considering XenServer for the first time, or looking at upgrading to 5.6 from a prior version, here’s some information on what’s new that will help you:

Dynamic Memory Control.  Let’s say you have a few XenServer hosts.  You need to spin up some more VMs, but your VMs are configured to use all available resource pool memory.  However, you know that some of the existing VMs aren’t using all the physical memory you’ve allocated.  With XenServer 5.6, you can set memory ranges for VMs so that you can squeeze the physical memory used for existing VMs in order to let new ones on.  If you find that one or more VMs operating near the lower limit requires more memory, you can increase the minimum level on the fly without rebooting.

Role-Based Administration and Audit.  You’re the primary XenServer administrator.  You have a junior admin that you want to provide a lower level of access within XenCenter so that they can start/stop/reboot/snapshot VMs without either 1. bothering you to do it for them all the time, or 2. Giving them full access to the XenCenter console where they have access to networking and storage configurations.  If that junior admin deletes a VM, you’ll have an audit trail with a record of this change, and when it was performed.

Heterogeneous Pools. Let’s say you have a pool of 5 XenServer hosts, which run on year-old hardware with Intel Xeon 5400 processors.  Now you buy a couple of new servers, which have new Intel Xeon 5500 processors. With XenServer you can join them to the same pool and enable XenMotion, HA, Shared Storage, and Workload Balancing. In the past, you could “force join” the newer servers to the existing pool, but you’d have to be careful not to XenMotion between different processor types.  This feature works with Intel processors with “Flex Migrate” capability and AMD processors with “Extended Migration” features.  Note that live migration between Intel and AMD does not work. We’ve added a new section on the HCL with the tested configurations.  Those that aren’t listed can be added by running through the Citrix Ready XenServer hardware test kit.

Memory Snapshots and one-click revert.  In addition to disk snapshots for backup, now you can snapshot the live running state of a VM.  In previous versions of XenServer, reverting to your snapshot was a multi-step process that was not ideal.  Now you just click “revert” in the snapshot manager.

Dynamic Workload Balancing with Power Management.  If you have a XenApp farm running 24×7,there is quite a bit of power wasted by those servers during nights and  weekends when only a handful of users are accessing applications.  Workload balancing can be scheduled to consolidate all of your idle XenApp servers on as few hosts as possible while powering off the newly vacated XenServer hosts. In the morning or after a weekend, those machines will power on and the VMs will be redistributed to handle the load.  Additionally, Workload Balancing includes a fully-automated mode with some new configuration options.  Example: if you have some VMs that you don’t want moving around, simply start those VMs on a specific host and exclude that host from WLB computations. 

Increased scalability.  We’ve doubled support limits for logical processors and memory to 64 and 256 GB, respectively.  Up to 16 NICs per host are supported as well. 

Updated Support for Provisioning Services (PVS).   PVS 5.6 has been updated, and includes a helpful new vDisk imaging wizard.   XenCenter is now more aware of PVS boot scenarios, namely through “boot from network” options in the new VM setup wizard.  One thing we’d like people to try (call it a “Tech Preview”) is streaming of XenServer bits themselves, in addition to VMs.  The eventual goal here is to greatly simplify management of XenServer updates and upgrades, just as PVS has done for XenApp and XenDesktop VMs. 

Enhanced XenCenter.  Did you run the XenDesktop setup wizard incorrectly and create a bunch of VMs that you now need to delete?  Use the multi-select feature, right-click, and select “delete.”  Need to start or shutdown a bunch of VMs at the same time?  Another good use for the multi-select option.  Other useful additions include one-step “VM move” (powered down) from array to array. Try right mouse clicking on a custom template and select “Instant VM from template.” You won’t be prompted to accept all the defaults, which you probably click right through anyway. 

Enhanced support for iSCSI arrays with multi-IQN / IP configuration.  DataCore SANMelody is an example of an iSCSI array that advertises multiple IQNs with multiple IP addresses.  With 5.6, we aim to make the setup of XenServer with SANMelody arrays much easier with the wildcard IQN scan option.

OEM edition simplification.  We used to assist with the creation of HP and Dell-specific versions of XenServer, which they shipped onboard their servers.  This had some issues.  One key example: though “Update” releases were made available for OEM editions, individual hotfixes were not.  No more.  Now we have one set of bits and HP and Dell apply hardware specific “supplementary packs” which contain their management agents and other hardware-specific components.  You can also support BIOS locking if you have an OEM version of Windows that you want to run as a virtual machine on your XenServer host.

Advanced Edition.  HA, Dynamic Memory Control, Alerting, and Performance History for $1,000 per server. Note: for a full list of the features in each edition (including Free) see here:

Server-based pricing. This isn’t “new” per se, however it’s starting to matter a lot more when you compare costs of XenServer and vSphere on some of the latest servers.  Dell R815 and HP DL385 G7 servers now ship with 12-core Opteron 6000 processors.   The problem for VMware customers is that they won’t allow you to run vSphere Standard or Enterprise Edition on those servers.  In other words, VMware hates Moore’s Law.  With XenServer, we don’t care how many cores or sockets the server has; you pay the same price with any configuration.  Citrix loves Moore’s Law.

Initial SR-IOV platform support for NetScaler VPX.  If you’ve got a server with an Intel SR-IOV capable NIC, you will soon be able to achieve near line-speed network performance to a XenServer virtual machine.  Initial tests within Citrix have shown ~ 108 Gbps of aggregate bandwidth to a NetScaler VPX virtual machine.  Note that the real benefit of this will arrive when we have a version of the NetScaler VPX that can use this platform capability (later this year).

StorageLink Site Recovery.  You’ve got a secondary site where you want to replicate all your virtual machines in case disaster strikes your primary site.  StorageLink Site Recovery simplifies the process of setting up this replication and recovering virtual machines in the DR site. Check the StorageLink HCL for arrays that initially support Site Recovery.

Citrix License Server integration.  Paid versions of XenServer now require a Citrix License Server.  Here’s what you need to know:

1. The Free version of XenServer continues to use the file-based activation process, so a license server isn’t required if you are using Free XenServer.

2. Unlike with prior versions of XenServer, licensing is enforced.  Before you upgrade any existing 5.x systems to 5.6, verify that you have the right number of licenses allocated to you via your mycitrix.com account. Note that there is a 30 day grace period after an upgrade, which gives you plenty of time to get your License Server set up.

3. In addition to the existing Windows-based License Server, we’re making a License Server virtual appliance available as well.  Just import it, run through a short configuration, and use a browser to upload your license files. 

For more information on 5.6 licensing, see CTX125301.

Was anything removed from the product in 5.6?

Not much.  The legacy Linux P2V tool in the installer is gone, though it wasn’t of much use any more since it only worked for very old distros. We’ve also dropped Debian Etch (4.0) support since it no longer receives security updates.  Those of you who look closely might find that the new “Demo Linux VM” template is, shall we say, eerily similar to Debian Etch.  It’s not recommended for production use, and we have this solely because so many of you told us you liked the built-in Linux distro for testing and demonstration purposes.

What’s not available quite yet?

While nearly everything in XenServer 5.6 is available today, a couple of things have yet to be posted:

  • Citrix License Server Virtual Appliance.  If you don’t already have a Citrix License Server running in your environment, you may want to wait to upgrade until this virtual appliance is available.  It will be posted no later than June 30.
  • Updated Lab Manager.  This will be available by June 4.

And though we’re shipping XenServer 5.6 today, we’ve already started work on the next couple of releases.  Stay tuned for more on “Project Cowley” and “Project Boston.”

Bill Carovano
Product Management, XenServer