I have one VNX5300 which has 8 iSCSI port, I want to connect my ESXi server to it now. In "vShpere Client" --> "Configuration" --> "Storage Adapter" --> "Dynamic Discovery", I need to add only 1 iSCSI ip so all the 8 can be automatically detected, or I need to add all the 8 iSCSI ip? If I only add 1 ip, will it be failover (so my ESXi can still reach it) in case storage processor A on VNX fails?
Thank you very much for the help, any advice is appreciated!
The iSCSI discovery protocol says you only need one IP address on the array to discover all the ports on the array. The VNX will return all SP ports configured with IP addresses..
Take a look at Support Solution emc245445 for iSCSI Best Practices for connecting hosts using iSCSI. For VMware and VNX see "TechBook: Using EMC VNX Storage with VMware vSphere" - see pages 38 and 42.
so what if I enter only 1 of the iSCSI server ip addresses and for whatever reason that ip address dies on me? Will ESX still be able to reach the other ip addresses?
Let me start by quickly mentioning that Dynamic Discovery is a way to simplify populating the Static Discovery list. Once populated it is no different than if I manually added them to the Static Discovery list individually. Any existing paths identified by Dynamic Discovery will persist. Unless you are adding new paths on a regular basis (maybe??? and yes I'm digging deep for an argument as to why), there really isn't any reason to add more than one Dynamic Discovery IP as the VNX will return all configured iSCSI targets from the array which we've all seen before.
Technically (no need to try), once (dynamically) discovered and you are fine with the list as seen in the Static Discovery tab, the sessions are logged in and LUNs available across the active paths, you could delete the entry in Dynamic Discovery. Again, at this point you are no different than if you manually added them yourself. You should also be able to reboot and they will persist. Please don't try because, for instance, I don't know if maybe you disabled Delayed Ack at the Dynamic Discovery level under the Advanced options so that then propogates to the individual Static Discovered entries (maybe because you chose for some reason not to disable it at the iSCSI adapter as a whole), I'm not 100% certain without testing if the child would recognize that. I will suggest though that hopefully this use case where it was set at one level but you remove that layer has been considered, and that the setting propogates and persists to the leaf nodes (individual sessions).
Does this make sense?
Cool! The thing is that I had to attach 2 ESX hosts (to a VNXe 3300) using iSCSI for the very first time. I'm familiar with HBAs and FC, but iSCSI was new to me.
So thank you for explaining, it sure makes sense
btw, I was only judging myself when I asked. Wasn't sure if what was in my brain translated to paper properly. Lol.
John, I forgot to welcome you to the forums and above all thank you for being an EMC customer!
LOL: John asked 1 question (his only post so far) and he got "spammed" with answers.
John, if you're listening: welcoe to the forums indeed. Why not introduce yourself in the "coffee break section", here: https://community.emc.com/thread/170567?tstart=0
Thank you guys, the information you provided is very useful!
I have tested that I only need to add 1 iSCSI ip (I use the iSCSI port A00's ip in VNX) in "Dynamic Discovery" and all the 8 ip can be automatically retrived. The next step I plan to test its redundancy, I will try to manually unplug some of the iSCSI port on the VNX and see if ESXi still able to access it. This means if the iSCSI ip in dynamic discovery is lost, ESXi will try other 7 path to access the VNX.