Re: [Qemu-devel] [Qemu/Virtio-scsi]The feature of 'raw device mapping' cannot isolate the LUN to the owning virtual machine

[Qixiaozhen]

> On Mon, Jan 27, 2014 at 02:50:04AM +0000, Qixiaozhen wrote:
> > A instance was created by virsh command in the CentOS 6.4.
> >
> > The LUN in the Storage Array Network(SAN) was attached to the instance
> with the following xml.
> >
> >     <disk type='block' device='lun'>
> >       <driver name='qemu' type='raw' cache='none'/>
> >       <source
> dev='/dev/mapper/360022a110000ecba5db427db00000023'/>
> >       <target dev='vdb' bus='virtio'/>
> >       <address type='pci' domain='0x0000' bus='0x00' slot='0x06'
> > function='0x0'/> </disk> <controller type='scsi' model='virtio-scsi'/>
> >
> >
> > A scsi report command was executed in the instance, for example "sg_luns
> /dev/vdb". However, It returned the list of the Luns in the SAN.
> >
> >
> > 1)       The unrelated luns in the SAN were not isolated in the instance.
> > address@hidden ~]# sg_luns /dev/vdb
> > Lun list length = 80 which imples 10 lun entries Report luns
> > [select_report=0]:
> >     0000000000000000
> >    0001000000000000
> >     0002000000000000
> >     0003000000000000
> >     0004000000000000
> >     0005000000000000
> >     0006000000000000
> >     0007000000000000
> >     0008000000000000
> >     0009000000000000
> 
> You are using virtio-blk with SCSI-passthrough, not virtio-scsi (it's 
> confusing but
> libvirt type='block' device='lun' means virtio-blk).  This feature has fallen 
> out of
> favor and is generally best replaced with virtio-scsi instead of virtio-blk.
> 
> If you do not require raw SCSI commands from the guest, then change
> device='lun' to device='disk'.
> 
> What exactly are you trying to do?

VMware document said that 'In physical mode, the VMkernel passes all SCSI 
commands to the device, with one exception: the REPORT LUNs command is 
virtualized so that the VMkernel can isolate the LUN to the owning virtual 
machine.'

So I want to test the very RDM feature in Qemu.

With Paolo's kindly help, a mistake was found in the configuration. Thanks for 
all your help.

Sincerely,