XenServer Storage Note for NetApp, EqualLogic Devices

Like many other virtualization administrators, I frequently have to keep up on the big players in the virtualization space. With Citrix's release of XenServer 5.5, a new option exists for many in the enterprise-class virtualization. Citrix's offering for free type-1 hypervisor-based server virtualization is the best offering from the big three players. This offering has been strong through the years, but I came across one note that should be passed along regarding storage for free XenServer implementations.

For XenServer implementations planning to use NetApp or EqualLogic storage, functionality for these storage devices is limited to standard fibre channel, iSCSI or NFS storage repository (SR) functionality. This does not allow XenServer to use the native storage APIs for these devices. The XenServer administration guide states:

NetApp and EqualLogic SRs require a Citrix Essentials for XenServer license to use the special integration via the NetApp and Dell EqualLogic SR types, but you can use them as ordinary iSCSI, FC, or NFS storage with free XenServer, without the benefits of direct control of hardware features.

Citrix has a different perspective on storage. I'll admit that I am quite the fan of vStorage VMFS, which is the most underrated technology VMware has ever made. Citrix's perspective is not to build a clustered file system, but to let the storage product's APIs be utilized for optimal performance. Comparatively, VMFS is free with ESXi and can be used across free and managed (HA/DRS/vCenter) storage zones.

Is this the end of the world? No. Is this new to version 5.5? No. Citrix still has the best free offering in my opinion. However, this is something you should know if you are planning on using the free offering critically in your implementation.

Posted by Rick Vanover on 07/20/2009 at 12:47 PM