MULTI PATH SUPPORT WITH VMWARE ESX 3.5U4 ?

[jkieffer72]

I am doing an evaluation of the Enterprise Edition product with my VMWare ESX 3.5 (Update 4) systems.

I have installed a fresh copy of Windows Server 2003 (all Windows Updates and latest drivers I could find) onto a spare server.
Starwind Server Specifications:
IBM x346
Dual 3.06Ghz Xeon CPU
1GB RAM
2 Dual port Intel PRO/1000 MT Ethernet Interfaces (one on motherboard, one add in card)
RealTek based Gigabit Ethernet Card
IBM ServeRAID 6i RAID Card
2x 36.4GB 15k RPM SCSI Drives (RAID1 - Drive C:\ for OS)
3x 73GB 15k RPM SCSI Drives (RAID5 - Drive D:\)
1x 300GB 10k RPM SCSI Drive (RAID0 - Drive E:\)

I have some experience configuring iSCSI connections; so I'm fairly comfortable with the technologies involved.

My network environment is divided into several seperate network segments/subnets.
192.168.209.x - Main network segment, Default vLAN (1)
192.168.201.x - SAN Segment 1 - vLAN 201
192.168.202.x - SAN Segment 2 - vLAN 202


I've configured the StarWind Server (BLASAN10) network with the following connections:
192.168.209.17 - Realtek Gigabit Card
192.168.201.17 - Intel PRO 1000MT add-in card; port 1
192.168.202.17 - Intel PRO 1000MT add-in card; port 2

I have three VMWare hosts; but am concentrating on just one to start with...
BLAVMS12 has two built in NIC ports and two single port add-in NIC cards.
vSwitch0 is configured to connect to the LAN on port 1 of the built in NIC (vmnic0); a service console is defined as vswif0 (192.168.209.32); there is also a VMKernel port (192.168.209.33)
vSwitch2 is configured to connect on on of the single port add-in NICs (vmnic2); service console port (vswif1) is at 192.168.201.32; a VMKernel port is defined as 192.168.201.33
vSwitch3 is configured to connect on the other single port add-in NIC (vmnic3); a service console port (vswif2) is at 192.168.202.32; a VMKernel port is defined as 192.168.202.33

I am using the iSCSI software initiator built into VMWare. I haved added 192.168.201.17 and 192.168.202.17 as portals under dynamic discovery.

I defined a target in the Starwind Console; 100GB virtual file on the RAID5 based drive D:\. Target name is defined as "r5test". Followed recomended settings; async mode; allow multiple connections, etc as found in the white paper.

I am able to connect to the target; but VMWare sees only one path on 192.168.201.17. I was expecting the system would also see the path on 192.168.202.17.

I also tried adding a secondary IP address (192.168.201.18) to the same NIC port that has the 192.168.201.17 assignment. Then added the 192.168.201.17 portal for dynamic discovery in the VMWare software target. This as not recognized as an additional path either.

Am I missing something, or are multi-path connections not supported in VMWare? I did some searches and did not find any thing relevant.

I feel Multi-pathing is critical to my environment for load-balancing, fault-tolerance, and in some cases increased bandwidth.

I saw that StarWind supports NIC teaming; but my understanding is that VMWare does not support NIC Teaming for iSCSI connections. I want to stay as close as possible to a supported configuration.

I took a look thru the log files; I don't see anything about logons being attempted on the 202 segment; everything seems to be going thru the 201 segment.

I am going to try connecting with the Microsoft iSCSI initiator and see if the MPIO is working there.

Please advise ASAP.

Thanks
John Kieffer

[jkieffer72]

Just tried the Microsoft iSCSI initiator; no luck with MPIO there either.

I do have the options to select the 209, 201 or 202 segment address as the Source IP; but the only target portal that shows up is 192.168.201.17 / 3260

I must have something not quite right?

[Robert (staff)]

Hello John,

To tell the truth, we have not really investigated using MPIO for ESX 3.5. For Windows Server MPIO - there is a document by the below link:

http://www.starwindsoftware.com/images/ ... d_MPIO.pdf

Perhaps, the instruction below would help (this is from VmWare ESX 3.5 Help):

1. Click the arrow next to the Inventory button in the navigation bar and choose Hosts and Clusters.

2. Select the host and click the Configuration tab.

3. Click Storage.

4. In the Storage list, right-click a datastore and choose Properties.

5. Click Manage Paths.

6. To set the multipathing policy:

a. Click the top Change button.

b. Select Fixed or Most Recently Used (default).

c. Click OK.

7. If you set the multipathing policy to fixed, specify the preferred path:

a. From the paths list, select the path to designate as preferred.

b. Click the bottom Change button.

c. In the Preference pane, select Preferred.

If Preferred does not appear as an option, make sure that the multipathing policy is set to Fixed.
d. Click OK.

8. Click OK.

9. Click Close.

We will investigate that more closely and provide you with additional information shortly.

Alternatively, maebe someone from the community has faced with this issue before?

Thanks,
Rob

[Robert (staff)]

By the way, how many connections can you see in the management console on the target side? (Each connection should be lightened by a globe sign under the target's name).

Thanks,
Rob

[jkieffer72]

I am seeing just one connection.

Note; in the Microsoft Initiator; I am seeing only the 192.168.201.17 address as an option in the Target Portal. The documentation you referenced indicates I should see multiple options here. (Your example used 192.168.1.1 and 192.168.2.1)

[jkieffer72]

Tried uninstalling (including cleaning up the registry) and re-installing; no change.

A little more information though...

I did get multiple targets to show up the first time I make a connection to the imagefile device. I made this happen by choosing the advanced option when configuring the Target Portals on the Discovery tab and specifying the Source IP as the individual sub-nets.

Now when I go into the Target I can specify which portal to use (209, 201 or 202) segment; but can only connect from a single segment. If I try to make another connection I get an error "Too Many Connections".

The iSCSI initiator I am trying to use is on the same machine; maybe this is causing the issue. I do notice that the source IP of the connection is showing as 0.0.0.0/1787.... I don't really have another Windows Server to test with handy. I tried from a XP client; but XP does not support MPIO at all; the options are greyed out.

I guess I will try the other way around; I will make the XP Box the Target and use the Server 2003 as the initiator to see if the MPIO works then.

[jkieffer72]

Still no luck; as soon as I make one connection; the subnet that IP address is on becomes the only option for the portal. i.e.; if I connect to the target portal 192.168.201.119, the target portal 192.168.202.119 is no longer an option, only 192.168.201.119.

[jkieffer72]

OK; I think I figured it out. The Multipath/MPIO does not allow multiple connections to the same session; rather you must logon multiple times, creating multiple sessions...

This works entirely different than the last device I was testing where there were multiple connections to the same session.

I think I've got the Windows MPIO portion of things figured out.

I don't think the VMWare Multipath works the same way; at least not in version 3.5. I believe there are changes to the multipath IO in vSphere (version 4); but I have not installed that for testing just yet.

I have a call scheduled for tomorrow morning with someone in support.

[Robert (staff)]

Hello,

We are glad you were able to resolve it and shared it with the community!

Thanks
Rob