Presenting LUNs to VM Host for VM Guests

[melvyn burnard]

>>The extra LUNs get presented to the VM Host I then present them to the VM Guest and no reboot for the Guest is required? Just an ioscan and insf -e?

Yes, provided that adding these LUN's does NOT cause a new "scsi card" to be installed in the Guest machine.

[N Ward]

Thanks Melvyn, how can I check if this is likely to happen?

[melvyn burnard]

look at each VM in detail, and see what the current addresses are for each backing store. Remember that the VM sees each backing store as a SCSI disk, so when adding to a VM, unless you overide the configuration by supplying a bus/target setting (middle of the 5 fields in the syntax) then it starts with SCSI ID 0, and goes up to 6, 7 being the virtual scsi card if I recall. So check whether adding a further backing store may go higher than this, in which case it should "install" a new virtual scsi card which requires a reboot of the Guest to recognize it

[N Ward]

I've had a look at each VM and they all have one adapter present SCSI Id 0-7. It currently has 3 devices using it, leaving ids 4-7. spare, so I guess this should not be a problem.

[melvyn burnard]

correct. As long as you do not specify the optional fields, as in:
disk:scsi::disk:/dev/rdsk/cxtydz
Then it should just use the next address

[N Ward]

I have added the first LUN to the Guest and it has asked for a reboot, which I wasn't expecting.

"hpvmmodify: Unable to dynamically create device....... - Protocol error" then asks for a reboot.

Command used:

hpvmmodify -p1 -a disk:scsi::disk:/dev/rdsk/c20t0d5

[N Ward]

No-one experienced this before?

I was hoping given the configuration and the fact we had available slots on the VM that no reboot was required. This message seems to contradict that..

[Torsten.]

I have to check the manual again, but I guess this online feature starts with version 4.0.

[Torsten.]

The manual says (version 3.5 also):

All types of virtual storage devices can be added and removed dynamically fromvirtualmachines.
That is, virtual disks, virtual DVDs, tapes, media changers, and CD/DVD burners are all
hot-swappable.However, the virtual storage adapters are currently not hot-swappable. Therefore,
if all the virtual storage adapters are full, you must reboot the virtual machine when you add
additional devices.

[N Ward]

Thanks Torsten, RTFM I guess, but I did already have some knowledge about the adapters, hence I looked at the Guest first.

There is capacity so it should have taken the next available ids.. It doesn't make sense.. I will try and post the ioscan output for verification..