14 Nov
2013
14 Nov
'13
4:33 p.m.
On 11/14/2013 09:09 AM, Paul Jansen wrote: > Hello Stefan. > Thanks. I understand qemu supports other scsi adapters however. See > this > <https://www.redhat.com/archives/libvir-list/2013-March/msg01254.html> > post from earlier this year. > That post makes reference to the following hbas: auto, buslogic, > ibmvscsi. lsilogic, lsisas1068, lsisas1078, virtio-scsi, vmpvscsi. > The post is referring to libvirt, so the number of adapters may be > related to the various virtualization backends that libvirt can > interface with. > > There are numerous references to qemu/qemu-kvm supporting other scsi > adapters as well as AHCI SATA. I installed the Centos 6.4 based node, > so perhaps the Fedora 19 based node has a newer qemu that supports more > of these features? I might see if I can do an install of the Fedora 19 > based node tomorrow. > > Ayal mentioned using 'hooks' to interface with qemu to possibly create a > VM outside of the definitions that Ovirt allows. If I am understanding > this correctly - how do I do this? Am I to expect some interface > inconsistencies in the ovirt portal I I view a 'custom' VM like this? hooks are compatible with the ui. you'd define a custom property with scsi=xxx or something like that. see for more detials: http://www.ovirt.org/VDSM-Hooks > > So, in short - is there the potential for me to create a VM in ovirt > that has a SCSI/SAS/SATA HBA and attach disk(s) to it (other than the > virtio-scsi HBA which is not supported under EL5)? > > > On Thursday, 14 November 2013 11:22 PM, Stefan Hajnoczi > <stefanha@redhat.com> wrote: > On Thu, Nov 14, 2013 at 02:39:33AM -0500, Ayal Baron wrote: > > > ----- Original Message ----- > > > > Hello Itamar. > > > > The specific use case is a particular propriety filesystem that > needs to > > > > see > > > > a scsi device. It will do scsi inquiry conmmands to verify > suitability. > > > > In talking to the devs - of the filesystem - there is no way > around it. I'd > > > > previously tried virtio-block - resulting in the /dev/vd* device > - and the > > > > filesystem would not work. > > > > > > > > From doing a bit of web searching it appears the kvm/qemu > supports (or did > > > > support) an emulated LSI scsi controller. My understanding is > that the > > > > various virtualization platforms will emulate a well supported > device (by > > > > the guest OSes) so that drivers are not an issue. For example > this should > > > > allow a VM on Vmware vsphere/vcenter to be exported to Ovirt and > have it > > > > boot up. The potential for further optimising the guest is there by > > > > installing ovirt/qemu/kvm guest utils that then allow the guest OS to > > > > understand the virtio nic and scsi devices. The guest could then > be shut > > > > down, the nic and scsi controller changed and the guest booted up > again. > > > > You can do the same thing in the Vmware world by installing their > guest > > > > tools, shutting down the guest VM, then reconfiguring it with a > vmxnet3 nic > > > > and pvscsi scsi adapter, then booting up again. > > > > It does seem somewhat inconsistent in Ovirt that we allow a > choice of Intel > > > > e1000 or virtio nics, but do not offer any choice with the scsi > adapter. > > > > > > virtio-scsi support was just recently added to oVirt to allow for scsi > > > passthrough and improved performance over virtio-blk. > > > I believe the emulated scsi device in qemu never matured enough but > possibly > > > Stefan (cc'd) can correct me here. > > The only supported emulated SCSI HBA device is virtio-scsi. It was Tech > Preview in RHEL 6.3 and became fully supported in RHEL 6.4. virtio-scsi > is not available in RHEL 5. > > > Stefan > >