Citrix XenServer is a virtualization platform comparable to Hyper-V and vSphere, though it's not as widely used. In Citrix Systems Inc.'s latest version, XenServer 6.1, features such as storage live migration and a direct VMware conversion tool are helping the Citrix platform become more relevant in the virtualization market, which is seeing an increase in mixed-hypervisor environments. While the storage in a Citrix environment doesn't necessarily vary from that of VMware or Microsoft, how the storage is managed and the best third-party tools for the environment do differ.
In this guide, you'll learn about Citrix XenServer management: what tools Citrix and third-party vendors can provide to ease Citrix XenServer storage management; how to enhance storage performance in a Citrix virtual server environment; the common problems that can occur; a description of the Citrix XenServer infrastructure; and how the Citrix XenServer StorageLink option provides a more integrated way to connect your virtualized server to a SAN.
Table of contents:
Because virtual machine disk image (VMDK) files reside in the XenServer environment, it's important for administrators to understand how storage is recognized. XenServer environments organize storage into Storage Repositories that contain both physical and virtual block devices. A database is also created to allow hosts to connect to the storage via IDs assigned to the physical devices. A common problem is a mismatch between the IDs on the XenServer database and those of the physical storage, making them inaccessible. In this tip, van Vugt details the Citrix XenServer infrastructure and how to overcome the mismatched ID issue.
Citrix XenServer's StorageLink technology lets administrators integrate the SAN with the Citrix environment, allowing for additional storage options such as cloning, data deduplication and snapshots. Because StorageLink can automatically detect iSCSI and Fibre Channel storage connections, storage array setup becomes much easier. Virtual machine (VM) setup is also easier because StorageLink uses templates to create VMs and then manage storage from those templates. While StorageLink is an optional add-on, Sander van Vugt argues it can be extremely beneficial to environments with a large number of VMs.