Fixed: Discovered iSCSI LUN not attaching to host iSCSI adapter

[ddawson20111014]

We've created an iSCSI LUN with 1 TB target on a Synology NAS. When I added the NAS's IP address for dynamic discovery, on the static discovery tab all the LUNs appear. I close the properties of the iSCSI initiator and expect to see LUNS listed under the Devices/Paths. None are showing up.

Our setup:

* Synology RS814+ with 4 x 4 TB disks.

* This LUN is a 1 TB LUN with options: Thin Provisioned: Yes, Advanced LUN features: Yes, LUN allocation unit size: 8192. Status is Ready.

* This target does not have CHAP enabled, no masking, Default privileges: Read/Write.

* The ESXi host is 5.0.0 build 131175 with DAS and an external SAS array. We just added a new vSwitch with one adapter for iSCSI.

I followed the iSCSI troubleshooting KB article and reviewed articles at vmguru, Synology and others.I'm really not sure which direction to go in now. I have mapped this LUN to a Windows Server so I think we're looking at some limit in our ESXi host. I am trying to get a service window to simply reboot our host machine and maybe even the NAS.

What we want to see:

What we see instead:

[dhanarajramesh]

in the second image i can see the IQN ends with snapshot.  is this snapshot LUN from the original LUN, if yes you need to re-signature it. follow this KB 

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=101138...

[ddawson20111014]

Thanks for the reply. We actually got it working in an unexpected way.

More info: our host only has a single dual-NIC adapter. The production traffic for guests and our iSCSI is on the same LAN. I had set one for iSCSI and one for guest networking on this same subnet. Each NIC was connected to a single switch.

After the reboot I checked again. I added the NAS NIC addresses back into Dynamic Discovery and noticed that the Static tab showed all LUNs as before. It appeared that the reboot didn't solve the problem. I did some digging into other possible steps. I followed these three articles. Those ruled more things out but didn't fix them still. I then realized that I didn't have to separate the NICs. I put the iSCSI NIC back into our guest VM switch. Then I kept digging and noticed that there was an error message when scanning:

Login to iSCSI target iqn.2000-01.com.synology:dcpcsbhqx-n0001.target-1.asigradata on vmhba35 @ vmk1 failed. The iSCSI initiator could not

establish a network connection to the target.

Login to iSCSI target iqn.2000-01.com.synology:dcpcsbhqx-n0001.target-1.archive on vmhba35 @ vmk0 failed. The iSCSI initiator could not establish a

network connection to the target.

At some point after this I noticed that all of a sudden our LUN showed up. It was available and I was able to add it as a datastore, format as VMFS and put it into production. I'm still curious why it didn't work with the single NIC. Also curious why I saw several instances of above errors and then it just mounted. But glad it's working now.