how to provide vm's access to FC SAN through the host HBA module?

chakoshi · 03-07-2010, 10:16 AM

Hi,
does any body got any experience on setting up a virtualized environment in which the vm's can access a fiber channel SAN storage? the host access the SAN through its own HBA, but the hba is not recognized inside the virtual machines (KVM virtual machines). does any one tried such a scenario? I use ubuntu on my systems, both host and guests. thanks.

OdinnBurkni · 03-17-2010, 05:49 PM

Hi.
I'm not familiar with the KVM solution but we use VMWare ESXi and run several CentOS servers on that and also some Windoze servers. We used to have a Wind... server running on one blade but moved it to VM and we were able to make the logical drives on the SAN (which were available to the server when it was on a separate blade) available to the Wind... server on VM. Not sure it's what you're asking but maybe it points you in some directions...

chakoshi · 03-18-2010, 02:33 AM

Hi
you are right, vmWare works well with hba's, and they are simply accessible through the guest system(at least windows guests). and I'm trying to do the same on kvm.

dyasny · 03-19-2010, 01:00 PM

what you need is called PCI passthrough. It allows you to provide a VM with a PCI device. This is still not supported on RHEL/CentOS afaik, but in the newest versions should be possible.

nikwax · 04-11-2010, 02:15 PM

Quote:

Originally Posted by chakoshi

Hi,
does any body got any experience on setting up a virtualized environment in which the vm's can access a fiber channel SAN storage? the host access the SAN through its own HBA, but the hba is not recognized inside the virtual machines (KVM virtual machines). does any one tried such a scenario? I use ubuntu on my systems, both host and guests. thanks.

Just curious - why would you want to have the VM access the SAN directly? Would it not be easier to abstract that part away and have the VM running on a virtual disk?

dyasny · 04-12-2010, 03:23 AM

nikwax, easier, but with the extra overhead, databases and other i/o heavy apps will suffer a performance hit

dyasny · 04-12-2010, 03:24 AM

nikwax, easier, but with the extra overhead, databases and other i/o heavy apps will suffer a performance hit

ncsuapex · 04-13-2010, 02:06 PM

We use VMware with CentOS 5.x as the guest OS. Then you need to install the iscsi-initiator-utils package and get the initiator name from /etc/iscsi/initiatorname.iscsi. There's more to it than that but Im not sure how to tell you how to do it on ubuntu.

nikwax · 04-13-2010, 03:22 PM

Quote:

Originally Posted by dyasny

nikwax, easier, but with the extra overhead, databases and other i/o heavy apps will suffer a performance hit

Sure - but you lose some of the benefits of virtualization. Many (most?) applications will work just fine virtualized, including databases and exchange servers. Big databases can be a special case though.