Rodos just reported on twitter that it looks like Boot From SAN is supported for ESXi. Unfortunately the KB article Rodos refers to in his tweet, kb.vmware.com/kb/1015000, is incorrect and Boot From SAN is not supported for ESXi. I’ve already reported this internally and hopefully the KB article will be fixed soon. The correct statement can be found in the install guide and is as follows:
Installing on a Fibre Channel SAN is supported experimentally. Do not attempt to install ESXi with a SAN attached, unless you want to try this experimental feature.
Source: ESXi Installable and vCenter Server Setup Guide (page 20)
For those interested in what “experimental” actually means, read this section on the VMware website.
Many people are keenly waiting for VMware to support ESXi on boot from SAN, in particular those diving stateless computing through technologies such as Cisco UCS.
If you are keen to see BFS for ESXi move from experimental to supported please make your view know to your VMware contacts.
P.S. We were so close … doh!
Thanks for clearing this up, even though you ruined joy for many of us.
Rodos, I will be sure to let my local VMware team know how much I want this. As a matter of fact I think I will bring it up as a point of discussion at my WI-VMUG meeting next week.
We boot from SAN almost all our ESXi 4 boxes using IBM blades, Dell R610 and R710 servers, IBM xSeries servers – all with Qlogic Dual Port HBAs and EMC CX3-20 storage without any issues. I don’t see any reason why it is still considered experimental feature.
Just curious about the SAN boot on ESXi, as long as we are using installable version of ESXi, actually what will be the concern that we could not boot from SAN? Technically the SAN booting parts will handle by the FC HBA adapter and the storage target itself. Would you mind to share more in details about this?
I know that it works technically, that’s the reason for it being experimental. But as long as the QA process isn’t completed and functionality can be guaranteed it will not be fully supported.
Matt Simmons says
This might be pedantic, but when the thing states “Do not attempt to install ESXi with a SAN attached, unless you want to try this experimental feature.”, does that really mean “with a SAN attached”, or with the OS drive being attached via SAN?
I would also assume that VMware is concerned about the “Manuals are for Sissies” people out there who present all of their VMFS LUNs and then complain because they install ESXi and it wipes everything.
The best practice to install or re-install any of the ESX servers, should always remove the unnecessary LUN and only presented the boot LUN. Even if you are not boot from SAN, you should always disconnect the FC connections to prevent the LUN been wiped which are shared across ESX clusters. Is part of the change control procedure the users should be considered.
Sean Borman says
Boot from SAN is supported in ESXi 4.1.
See the “What’s new in vSphere 4.1” guide here: