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Beyond Creedence - XenServer 2015 Planning

In a few weeks James Bulpin and I will be at the Xen Project Developers Summit in Chicago, and some of our discussions will be about the future of XenServer, and more importantly to the community "What comes after Creedence?". With the Creedence alpha program we're seeing a level of community engagement which has honestly exceeded my expectations. I attribute this to the significant improvements in the platform, but also the level of transparency we've had with respect to early access to pre-release builds.

While it was pretty obvious what we needed to do to make Creedence viable, your input is important to the future success of XenServer. With that in mind, we'd like to hear what platform improvements you'd find most valuable. When I speak of platform improvements, I'm thinking of things like storage, networking, core virtualization, performance, scalability and operating system support. I'm not thinking of things which can be classified as data center or virtualization management, so things like network management, disaster recovery, or virtual machine provisioning are out of scope. Based on the blog comments for the various alpha announcements, we already know that CentOS 7 dom0, NFS4 and Ceph are on your wish lists, but what else?

Internally we use a "How would you spend $100?" model to prioritize changes, and if you were interested in providing feedback following that model, it would be ideal. If you've never used this model before, it's pretty simple. Write down the things you'd want to see (optionally with a "why" beside them), and then given a budget of $100. Spend the $100 by allocating it to your desired functionality, and anything with a zero is removed. This has the benefit of focusing on the high value changes without worrying about complexity. If you'd like to provide input, please do so in the comments section below, and let's see what the future of XenServer in 2015 looks like from your perspective.     

Tagged in: Creedence Roadmap

Tim Mackey is a community manager and evangelist for XenServer within the Citrix Open Source Business Office and is focused on server virtualization and cloud orchestration technical competencies. He joined Citrix through the Reflectent acquisition in 2006, and served as architect and developer for Citrix EdgeSight; an end user experience performance monitoring solution. In 2007, Mr. Mackey became technical product manager for the EdgeSight product line and then in 2009 product manager for the XenServer self-service virtualization components. Since that time, he has held various roles within the XenServer team, and speaks regularly on topics related to the design of large scale virtual environments.


  • David Reade
    David Reade Wednesday, 30 July 2014

    Could Changed Block Tracking (CBT) be considered as a feature please to speed up incremental backups? We use Unitrends to perform backups to an NFS store every night incrementally which can take forever regardless of the amount of data backed up.

  • Guest
    Rachel Berry Sunday, 03 August 2014

    Yes, I think that sounds very useful and one I long desired

  • Guest
    Rachel Berry Sunday, 03 August 2014

    Yes, I think that sounds very useful and one I long desired

  • Keith Walker
    Keith Walker Tuesday, 31 March 2015

    CBT, the entire $100.

  • Andrew
    Andrew Wednesday, 20 May 2015

    $80 for CBT, $20 for online disk expansion.

  • Jarian
    Jarian Wednesday, 30 July 2014

    I like that NFS4 and Ceph are mentioned above.

    Reply Cancel
  • JK Benedict
    JK Benedict Wednesday, 30 July 2014

    I love this post!

    If I had $100 dollars, I'd spend $50.00 of it to roll in older PV tools for Legacy OS/App support as so I don't get stuck on a particular XenServer release.

    I'd spend $25 more of my time to make coalescing more dynamic: checking server stats to throttle cleanup (seconds to run/Mibs to coalesce).

    Lastly, I would use the remaining $25 to add shadow passwords: allowing non-root users to access XenCenter while logging their activity. Much like RBAC, this would help diagnose who/what/when in a multi-administrator environment.

    And I'd give my time away freely to help in all these aspects so the $100 comes back to the community and us!

    Thanks for this opportunity, Tim and we appreciate all you do!


    Reply Cancel
  • Guest
    Albert Wednesday, 30 July 2014

    If i had $100, I'd spend all for support Oracle Solaris under a new Xenserver

  • Guest
    Rachel Berry Sunday, 03 August 2014

    See my comment (Rachel), XenServer cannot support Solaris alone, you need to persuade Oracle, we would be happy to do so if the did.

  • Tobias Kreidl
    Tobias Kreidl Friday, 08 August 2014

    How about supporting an open Solaris variation instead, like OpenIndiana or Illumos?

  • Guest
    ONOV Wednesday, 30 July 2014

    Except it would then cost you $1000 per core per year to license running your Solaris VM according to Oracle's licensing models. :-(

  • David Taylor
    David Taylor Wednesday, 30 July 2014

    I'd have to say our key issues are around P2V conversion and more specifically Linux HVM to PV conversion. I'd probably spend about $35 on that. Linux support for XenCenter is also a major one, the current Linux clients aren't there for production yet, I'd put about $15 there. The other $50 I'd love to see hit a lot of small operational issues like screen buffer support for linux hosts and stability/recoverability following a hypervisor crash.

  • Tim Mackey
    Tim Mackey Thursday, 31 July 2014


    If you can give examples of the pain points in your "operational issues"; I'd like to hear them. I personally have a bunch of pain points I'd like to see addressed, and some of them have been around for years but have always tended to fall below the cut line for one reason or another.


  • David Taylor
    David Taylor Monday, 04 August 2014

    A lot of the issues have been around stability, visibility and migration. So for instance in a two Xenserver cluster we had an issue where we were doing a rolling update and the master was put into maintenance mode but didn't pass the master function to the second server correctly and we ended up with 4 isolated machines that then couldn't find their virtual disk correctly and consequently couldn't start.
    In terms of visibility just the errors being so generic, it would be much better to provide more detail in the XenCenter error log. Also graphing can be unpredictable sometimes it works correctly other times graphs just aren't there. So for me XenCenter is a big one especially the lack of a production ready linux client.
    And the last big thing is the conversion of linux hosts to PV from HVM. THe lack of a clear path to full virtualisation is really putting a crimp on our ability to move to Xen.

  • Tobias Kreidl
    Tobias Kreidl Thursday, 31 July 2014

    $30: Thin provisioning for block I/O (yes, Ceph can handle that) and NFS4 (YES!), $20: RAM Cache with Overflow to disk for MCS so XenServer can support it with that "other" provisioning service, $40: the ability to copy either running or shut-down VMs including storage to other locations and either leave them down if already running or start them up if not already running or copy from down-to-down state to provide easy, cheap ways of data replication and/or backup, $10: better granularity in XenCenter performance meter. Shucks, I'm already out of money...

  • Guest
    Tessio Fechine Sunday, 15 February 2015

    Don't XenServer already has thin provisioning?

  • Terry Wang
    Terry Wang Thursday, 31 July 2014

    If I had $100, I'll spend
    - $30 to upgrade dom0 user-space to CentOS 7 x86_64
    - $40 official support for running new Xen modes (especially for Linux): PVHVM (PVonHVM) and PVH (PV in HVM containers - new in Xen 4.4 and will stabilize). Benchmarking results show Linux PVHVM outperforms pure PV in many ways. PV is no longer the best mode for Linux guests.
    - $10 Btrfs as local storage option - probably as tech preview - See how cool it is in CoreOS (Linux + systemd + LXC + Btrfs + Docker).
    - $10 update e2fsprogs to support ext4 with Linux 3.10+, ditch ancient ext3 (local storage - thin provisioning)
    - $10 Certify more OSes , e.g. PV Ubuntu 14.04 LTS, RHEL 7, CentOS 7, Oracle Linux 7, openSUSE 13.1 etc. (in fact, if PVHVM is officially supported, this is not a problem)

  • Van Rue
    Van Rue Wednesday, 24 September 2014

    $50 for btrfs support

  • Guest
    Frediano Ziglio Friday, 08 August 2014

    - Ubuntu 14.04 Centos 7, RHEL 7 Oracle Linux 7 are going to be supported on Creedence.
    - There is an installer option to use ext4 instead of ext3, at least for root partition.

  • Andrew Cooper
    Andrew Cooper Thursday, 07 August 2014

    There is some crazy versioning with two packages in RHEL/CentOS 5.x alonge, e2fsprogs and e4fsprogs (which is e2fsprogs + ext4 support). 6.x and 7.x move back to the proper e2fsprogs with proper ext4 support. ext4 tools and support are present in exiting XenServer versions.

    PVHVM and PVonHVM are two different virtualisation mechanisms. PVonHVM most accurately describes Windows VMs with PV tools installed, while PVHVM describes a Xen-aware Linux operating system with a Qemu-based virtual motherboard. PVHVM takes advantage of some paravirualised interrupt delivery mechanisms which Windows doesn't.

    If you download yourself Creedence Beta 1, you might find some new templates to your liking. Unfortunatly, there are some core PVHVM Linux bugs (particularly around migrations) and still others lurking. Some patches have been submitted upstream (but none yet are in LTS trees, I believe).

    PVH is on the unstable side of experimental and it currently feels like every other commit to Linux or Xen breaks it in a new way. I personally have broken it twice with commits in seemingly unrelated places. It will be lovely when it works, but is a very long way off.

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Guest Sunday, 02 August 2015

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XenServer is the leading open source virtualization platform, powered by the Xen Project hypervisor and the XAPI toolstack. It is used in the world's largest clouds and enterprises.
Commercial support for XenServer is available from Citrix.