XenSource's XenEnterprise 4.0, announced today and available August 20, erases a number of shortcomings Paul Venezia noted in his July 9 review of XenEnterprise 3.2. These included lack of support for 64-bit guests, no live VM migration or automated load balancing, and in fact no support for shared storage, putting XenEnterprise well behind the curve set by VMware and even a few steps behind Xen-based rival Virt XenSource’s XenEnterprise 4.0, announced today and available August 20, erases a number of shortcomings Paul Venezia noted in his July 9 review of XenEnterprise 3.2. These included lack of support for 64-bit guests, no live VM migration or automated load balancing, and in fact no support for shared storage, putting XenEnterprise well behind the curve set by VMware and even a few steps behind Xen-based rival Virtual Iron (see Xen masters take aim at VMware). XenEnterprise 4.0 fills some of these gaps but not others, and some of the important details were left out of the press release (surprise). XenSource CTO Simon Crosby was kind enough to set the record straight with the following answers to my questions. Q: Does XenMotion automate load balancing, or are migrations triggered manually? A: XenMotion is manually initiated from the GUI, however it can be manually or programmatically managed via the XenAPI which offers bindings in Java, C, C# and the CLI, which offers 3 scripting language bindings. There are various plug-in products that will be announced by ISV partners and by XenSource as a result of its Symantec partnership, that deliver on the value propositions of HA, DR, DRS, and so on. Q: The 4.0 release “also supports up to 8-way SMP per guest, and leverages ACPI to support dynamic hot-plugging of CPU, network and storage into running virtual machines.” Is this also a manual operation? A: There is a very simple wizard that allows you to add hard disk storage or networking interfaces into a running guest VM. You have to identify what storage you want to use, and then you simply assign it to the VM, and it automatically shows up as “hot plugged hardware” in the guest, where you can assign it to various volumes etc. Nutshell, entirely automated via simple wizards. Q: Is XenMotion enabled in v4.0, or does it (and support for shared storage in general) await the integration of Veritas Storage Foundation? If enabled now, what flavors of shared storage are supported? A: Enabled now. Shared Storage Repositories include NAS, LVM over iSCSI, and LVM over FC, with the specific proviso that the LVM over FC support is an enablement statement subject to continued ongoing testing against the very large number of vendors’ products; we will support customers’ use of this only for storage subsystems that we have certified. Moreover the Veritas Storage Foundation product suite also simply plugs in as an SR type, and we believe is the way most customers really want to manage their SAN based storage. It also allows us to leverage the certification and testing that Symantec will do for the integrated product in its labs. Q: Does XenEnterprise support 64-bit Linux and 64-bit Windows guests? Any other 64-bit guests? A: In this release 64-bit Windows Server only; 64-bit Linux will come in a point release toward the end of the year. The key workload we want to host with 64-bit is the 64-bit 2007 releases of Exchange and SQL Server. Q: Veritas Storage Foundation will not enable incremental backups of virtual hard disks, will it?A: Symantec will certify Veritas Net Backup for XenEnterprise, as the preferred backup utility. I’ll take that last answer as an artful no. Or maybe it’s the answer to another question that I should have asked. Technology Industry