RHEL 5.0 migration poses problems

Users of Red Hat Enterprise Linux 5.0 have complained of problems with the operating system’s ability to migrate live virtual machines, as well as the lack of documentation and remote support tools for the OS, which was released in March.

The live migration of active virtual machines poses a thorny problem for many vendors, including Microsoft. The software giant announced last month that it was removing the feature from its ‘Viridian’ Windows Server Virtualisation technology, previously planned for the forthcoming Windows Server 2007 (Longhorn) OS.

Red Hat said that fixes for the migration problem are on the way, but it has not yet decided exactly when or how it will make them available.

“The live migration is already there, but it is not as strong with full virtualisation. We will get that in version 5.1 [which will] probably be out in the fall, though we do not have an official date yet,” said Red Hat software engineer Daniel Veillard. “Once we have remote support, the management tool can be extended to manage a dozen operating systems or more, and we can do graphical migration based on taking one domain to another. But we are not there yet.”

Red Hat chief technology officer Brain Stevens pointed out that the XenSource virtualisation technology used by RHEL 5.0 is very similar to that used by Microsoft’s Viridian, so it was no surprise that similar problems should arise.

“Both are based on standard hypervisors and paravirtualisation, so the two are largely consistent. We are not sure when this [live migration] will come to RHEL, possibly in version 5.1, but there are no promises,” Stevens said.

The company is doing its best to make sure RHEL 5.0 users can find relevant documentation, added Stevens, and will make more effective use of online knowledge bases in the future.

At last month’s Red Hat Summit, some RHEL 5.0 users doubted whether they would find a use for the virtualisation that the OS provides.

“Based on the few tests we’ve done with it, it is a great technology but at this point is not yet a great product. VMWare has worked with us for a bit longer and people are used to it. With Xen, you still have to struggle a bit, but we may consider it later as new products come out,” said one attendee.