In the 2011 Openworld, I had the opportunity to meet some of the Oracle cluster experts. In conversations, I found that when configuring LDOMs within a clustered environments, we could pass a complete "/dev/did/*dsk/d<num>" device directly to the guest domain.
Are there any notes/whitepapers that someone within Oracle could direct me to that elaborates this a little more? I can reach out via our regular pre-sales channels, but I'm posting here since I know the Cluster gurus frequent this watering hole :)
at first one question back to you to understand your configuration: where does the cluster live, what do you want to be clustered resources?
Reason for this question is that there are 2 ways to run Solaris Cluster in an LDOM environment:
1. You cluster the primaries/IO-domains and use guest LDOMs as cluster resources (plus other resources like DBs, etc).
2. Or you cluster guest LDOMs from several systems.
IT is not recommended to mix the two.
In case 2, as there is no cluster in the IO-domain, there is no /dev/did device that you can pass on to the guests. In case 1 there is, but I would have to check the docs.
I could not find out the exact answer, but I have a couple of thoughts to share.
1. There is no reason to believe that using the method you proposed would not work.
2. On the other hand, why would you want to use did devices and not cNtNdN devices?
Conceptually this should be identical, but using cNtNdN devices would have the advantage that they would work, even if you booted the IO domain without Solaris Cluster, e.g. in an emergency. I do not see that the did devices offer you any advantage. The guest only sees a virtual device and during the process of mapping a device to the guest, you have to chose a logical name as well. So I really do not see the benefit.
I chose to use the DID namespace because of it's simplicity. I can reference a /dev/did/rdsk/d<> and be consistent across the cluster. Also, since I'm using HA to cluster the LDOMs, I don't have to worry about bringing up resources on the Control domain (since all the FC storage I use is for guest domains). The control domains themselves (which are also the IO domains) have the internal drives of the T4-4 that contain the rpool etc.