iSCSI configuration

[JV1492]

I am having a hard time getting iSCSI up and running (I know, welcome to the club), and was hoping someone could shed light on some questions to help me in the right direction.

I have gotten iSCSI working before, on HP DL380 servers and an HP iSCSI disk array, so I know what it "should" be like. It was painful that first time around, as well.

I have been all over the posts, how-tos and step-by-steps, but I haven't seen some things explicitly stated.

My current environment is not the enterprise one I mentioned above.

It includes the following:

an IBM xSeries 346, with 16 GB of ram, an IBM RAID card, 2x72 GB disks and 4x146 GB disks, running Openfiler 2.99.2 (last release, updated with all patches). There are two built-in Gb nics.

a Dell Poweredge 1950 (III) with 32 GB of ram, 2x300 GB disks, running VMware 4.1u1. There are 3 Gb nics in there.

I believe Openfiler to be correctly set up as an iSCSI storage device. Volumes were created and mapped, and access was granted.

I enable software iSCSI on ESXi, point it at the Openfiler device, rescan, reboot, and recurse at the machines. Nothing appears. I know, the first rule is to speak nicely to the hardware.

Here are my questions:

1) Does the iSCSI interface on ESXi need to be on a separate vSwitch with its own nic ?

2) Does the nic need to be on a different subnet than the management interface ?

On the Openfiler side, which I realize is not the topic of this forum, if I set the IP to be on the same subnet as the ESXi iSCSI nic, which would be different from the ESXi management nic subnet, I can't get to the Openfiler management interface without a router.

I am asking what happens if you set up two interfaces on Openfiler in the Openfiler forum, although there is no mention of doing that in the documentation or any of the guides people have posted.

3) Is there any command line or utility I can use to confirm that a storage device is presenting IQNs and LUNs ?

Finally, if it occurs to anyone that I am overlooking something, feel welcome to point it out.

TIA

[weinstein5]

The answered to questions  1 & 2 is no but best practices is to have iSCSI traffic on a seperate subnet/vlan - I am more curious about your statement -

On the Openfiler side, which I realize is not the topic of this forum, if I set the IP to be on the same subnet as the ESXi iSCSI nic, which would be different from the ESXi management nic subnet, I can't get to the Openfiler management interface without a router.

Are the OpenFiler and on Different subnets? Can you ping the iSCSI vmkernel ports from OpenFiler? Can you vmkping the OpenFiler IP address?

I am thinking it is a network connectivity problem - wither lack of a router or misconfigure router -

[JV1492]

No, the configuration I used had both the ESXi addresses (host and iSCSI) on the same subnet as the Openfiler rmachine.  I can ping all around, between the VMware host, the Openfiler machine and the management workstation. No network connectivity issues.

Anyone know command line or utility tests to confirm iSCSI storage config and availability on the network ?

[chriswahl]

Nothing really special about an iSCSI packet, just standard layer 3. Make sure the required ports are open on the network, and possibly set your array to allow any IP to connect to your volume to iron out you aren't filtering the host's initiator somehow. If you've used a vmkping from the host to the array and it's successful, you've done all that is required from the host perspective.

Cheers.

[chriswahl]

If you're using dynamic targets on the ESXi host, it should find the targets for the IP of the storage array. This can be a good troubleshooting tool to determine if the network is not configured properly, as otherwise you won't see any targets.

I suggest using a unique subnet for iSCSI storage and making sure you have at least one vmkernel port set up on that subnet. This ensures that traffic does not traverse other vmkernel ports (since same subnet traffic never goes to the default gateway, which may not be the vmkernel port you want).

I have a four part series of articles on NFS traffic, but realistically iSCSI works nearly the same (unless you are using iSCSI binding on the host, which binds a vmkernel port to a vmnic).

http://wahlnetwork.com/2012/04/19/nfs-on-vsphere-a-few-misconceptions/

[rickardnobel]

JV1492 wrote:

I enable software iSCSI on ESXi, point it at the Openfiler device, rescan, reboot, and recurse at the machines. Nothing appears.

So you have entered the Openfiler IP address as a dynamic target? Do you see anything appear on the "Static" tab after this? You should be able to see the IQN name of the iSCSI target here.

After this, if you select the vmhba33 (or similar) do you see anything in the lower pane?

[JV1492]

yes, I entered the Openfiler IP as a dynamic target. I see nothing in the static tab. The lower pane doesn't show anything either, as would be expected if the tabs don't.

[rickardnobel]

JV1492 wrote:

yes, I entered the Openfiler IP as a dynamic target. I see nothing in the static tab. The lower pane doesn't show anything either, as would be expected if the tabs don't.

Are you sure you have configured the Openfiler correct? Perhaps not the ESXi host is on the allowed network list?

[JV1492]

I did include the ESXi host on the allowed Openfiler list.

[rickardnobel]

JV1492 wrote:

I did include the ESXi host on the allowed Openfiler list.

You mentioned that you had several vmnics on the same network. It might be that the host is using another vmnic than you expect.

[JV1492]

no, I said that I several physical NICs. There is only one vmnic in the networking config.

[rickardnobel]

Have you got the Openfiler iSCSI to work before, with other systems than ESXi?

[gprentice]

Had the exact same problem - couldn't see Openfiler iscsi target in ESXi.

In Openfiler, had the explicit IP address of the ESXi host (192.168.0.200) in the 'allow' Network ACL but couldn't see the target from the ESXi host.

192.168.0.200 was the iscsi initiator IP address in ESXi host, on the same vswitch as the management vmkernal & NIC (ESXI had single NIC in test lab)

The ISCSI target finally showed up when the entire IP range was added to the network ACL (192.168.0.0  255.255.255.0).

Hope this helps someone.

[JV1492]

is there a command line in XP that allows you to see the IQNs being advertised by Openfiler ? That would confirm that Openfiler is configured properly. Then I could work on the ESXi side.

[rickardnobel]

JV1492 wrote:

is there a command line in XP that allows you to see the IQNs being advertised by Openfiler ? That would confirm that Openfiler is configured properly. Then I could work on the ESXi side.

XP as in Windows XP? There is no native iSCSI initiator for XP, but there might exist some 3rd party tool. However, I do not think the IQN name is the problem here. If you have confirmed that you can reach the iSCSI Target with vmkping, but do not see anything on the static tab then I think it is because of bad permissions on the Openfiler.

Have you put only the ESXi host address on allowed? Could you try to add the whole subnet and do a rescan?