Daily life becomes our Zen training.—
Procedure for Resizing all the PvDs in a Catalog. The following points must be taken care while resizing the PvD: A PowerShell script is included in this release that allows you to resize all the existing personal vDisks in a catalog. The script iterates through the machines in. So, point number one – the size of the User and Profile partitions are static, not dynamic. Now, if you have, say a 20GB PvD, you will not necessarily want 50% of this for User Data as you may be using Roaming Profiles (why?!?), Citrix User Profile Management (:)) or another Profile Management system such as AppSense Environment Manager. All About Citrix.
- 1Y0-203 Citrix XenApp and XenDesktop 7.15 Administration Resource Guide. Section 4: Provision and Deliver App and Desktop Resources.
- Nicholas Rintalan has written a blog post on the Citrix blogs about the need of seperating the PVS stream to a separate LAN segment. Here's a grab of his post: Similar to what I did in my last article where I discussed fixed versus dynamic vDisks for PVS, let's first examine what our public documentation says about this so-called best practice.
Citrix XenServer isn't as popular as ESXi or Hyper-V. But if you already use Citrix products, you should think of Xen because you already have expertise with this vendor.
1. Brief history
On 13th January 2015 Citrix released XenServer 6.5, offering a 64bit Dom0 and significant networking and disk performance increase. The XenServer control domain is now able to directly access far more memory (RAM) and address more PCIe adapters than before leading to increased scalability and performance of the overall system.
Xen first public release was in 2003, became part of the Novell SUSE 10 in 2005 (later also Red hat). In Oct 2007 Citrix acquired XenSource (the main maintainer of the Xen code) and released XenServer under the Citrix brand. Version 5.6 was released in May 2010, 5.6 SP2 released May 2011, XenServer 6 in Sep 2011, XenServer 6.1 in Sep 2012 and XenServer 6.2 in June 2013.
2. Architecture
XenServer uses paravirtualization and hardware-assisted virtualization, requiring either a modified guest OS or hardware assisted CPU (more commonly seen as less restrictive and hardware assisted CPUs like Intel VT/AMD-V have become standard). The device drivers are provided through a Linux-based guest (CentOS) running in a control virtual machine (Dom0).
Fig. 1 – Citrix XenServer Architecture
3. What is the difference between XenServer and the open-source Xen Project Hypervisor?
The Xen Project hypervisor is used by XenServer. In addition to the open-source Xen Project hypervisor, Citrix XenServer includes:
- XenCenter – A Windows client for VM management
- VM Templates for installing popular operating systems as VMs
- vGPU
- Resource pools for simplified management of hosts, storage, and networking
- Enterprise level support
4. Re-introduction and Improvements to Workload Balancing
XenServer 6.5 sees the return of the WorkLoad Balancing (WLB) virtual appliance. WLB automates the process of moving Virtual Machines between hosts to evenly spread Network, CPU, and Disk loads to maximize throughput. WLB keeps a history of the usage of CPU, Disk, and Network for all VMs in the pool so it can predict where workloads can be best located. WLB gives system administrators deep insight into system performance, allowing infrastructure optimization.
5. XenServer 6.5 includes performance, scalability, usability, and functional improvements to vGPU.
XenServer will scale as your hardware grows with support for more physical GPUs per host – it now supports up to 96 vGPU accelerated VMs per host compared to 64 vGPU accelerated VMs in XenServer 6.2 SP1, further reducing the TCO for deployments.
6. In-memory Read Caching
Citrix XenServer isn't as popular as ESXi or Hyper-V. But if you already use Citrix products, you should think of Xen because you already have expertise with this vendor.
1. Brief history
On 13th January 2015 Citrix released XenServer 6.5, offering a 64bit Dom0 and significant networking and disk performance increase. The XenServer control domain is now able to directly access far more memory (RAM) and address more PCIe adapters than before leading to increased scalability and performance of the overall system.
Xen first public release was in 2003, became part of the Novell SUSE 10 in 2005 (later also Red hat). In Oct 2007 Citrix acquired XenSource (the main maintainer of the Xen code) and released XenServer under the Citrix brand. Version 5.6 was released in May 2010, 5.6 SP2 released May 2011, XenServer 6 in Sep 2011, XenServer 6.1 in Sep 2012 and XenServer 6.2 in June 2013.
2. Architecture
XenServer uses paravirtualization and hardware-assisted virtualization, requiring either a modified guest OS or hardware assisted CPU (more commonly seen as less restrictive and hardware assisted CPUs like Intel VT/AMD-V have become standard). The device drivers are provided through a Linux-based guest (CentOS) running in a control virtual machine (Dom0).
Fig. 1 – Citrix XenServer Architecture
3. What is the difference between XenServer and the open-source Xen Project Hypervisor?
The Xen Project hypervisor is used by XenServer. In addition to the open-source Xen Project hypervisor, Citrix XenServer includes:
- XenCenter – A Windows client for VM management
- VM Templates for installing popular operating systems as VMs
- vGPU
- Resource pools for simplified management of hosts, storage, and networking
- Enterprise level support
4. Re-introduction and Improvements to Workload Balancing
XenServer 6.5 sees the return of the WorkLoad Balancing (WLB) virtual appliance. WLB automates the process of moving Virtual Machines between hosts to evenly spread Network, CPU, and Disk loads to maximize throughput. WLB keeps a history of the usage of CPU, Disk, and Network for all VMs in the pool so it can predict where workloads can be best located. WLB gives system administrators deep insight into system performance, allowing infrastructure optimization.
5. XenServer 6.5 includes performance, scalability, usability, and functional improvements to vGPU.
XenServer will scale as your hardware grows with support for more physical GPUs per host – it now supports up to 96 vGPU accelerated VMs per host compared to 64 vGPU accelerated VMs in XenServer 6.2 SP1, further reducing the TCO for deployments.
6. In-memory Read Caching
In scenarios where golden images are deployed and VMs share much of their data, the few specific blocks VMs write are stored in differencing-disks unique to each VM. Read caching improves a VM's disk performance as, after the initial read from external disk, data is cached within the XenServer host's memory. This enables all VMs to benefit from in-memory access to the contents of the golden image, reducing the amount of I/O going to and from physical storage.
7. Updated Open vSwitch
XenServer 6.5 includes the latest version, OVS 2.1.3, which supports megaflows. Megaflow reduces the number of required entries in the flow table for most common situations and improves the ability of Dom0 to handle many server VMs connected to a large number of clients.
Fixed Or Dynamic Vdisks All About Citrix Download
8. Distributed Virtual Switch
XenServer 6.5 contains a new DVSC version from Nicira (DVSC-Controller-37734.1), and contains platform related security fixes (for example, OpenSSL and Bash Shellshock)
9. Lower Deployment Costs with Space Reclamation on the Array Space reclamation
Fixed Or Dynamic Vdisks All About Citrix Cloud
This feature allows you to free up unused blocks (for example, deleted VDIs in an SR) on a LUN that has been thinly provisioned by the storage array. It enables notifications of deletions within LVM to be communicated directly to the array. Once released, the reclaimed space is then free to be reused by the array.
Fixed Or Dynamic Vdisks All About Citrix Software
10. Live LUN Expansion
In order to fulfill dynamic capacity requirements, you may wish to add capacity to the storage array to increase the size of the LUN provisioned to the XenServer host. The Live LUN Expansion feature allows to you to increase the size of the LUN without any VM downtime.
