hanslad
Contributor
Contributor

Is Management Server required?

Hello!

My company has bought two ESX servers, each running on a DELL Poweredge 1955 blade.

The servers are connected to a DELL AX150 San through firewire.

My problem is that I am only able to connect one ESX server to a virtual disk (LUN?) at a time.

When I try to connect the second server (using "add storage...") the message "Warning: The current disk layout will be destroyed.All Files and data will be lost permanently"

The first server is ESX 3.5, The second is ESX 3.1

Is management server required to allow two ore more servers share same the disk/LUN?

Thanks in advance.

0 Kudos
7 Replies
FredPeterson
Expert
Expert

No, VirtualCenter is not required to share disk.

When you share disk between hosts, you don't have to "add" the disk, it should simply show up after a host reboot or if you scan for new LUNS and new VMFS volumes.

0 Kudos
hanslad
Contributor
Contributor

Well,actually I manage to connect to the LUN on both hosts.

But my problem is that I first have added a storage with vmfs filesystem to the host 1.

When I try to do the same on host 2 I get the error message. Maybe the attached files explain my problem.

All I want is to be able to read/write to same vmfs file system in both hosts.

0 Kudos
FredPeterson
Expert
Expert

Well I think your problem is that you keep trying to Add the storage. You don't have to. If the one host sees the LUNS as a properly formatted VMFS volume and that same LUN is zoned EXACTLY THE SAME to the other host, then the VMFS volume should just magically show up when you click "Rescan."

Answer me this. Does the path information on both hosts under the Details section of the Storage Adapters look identical? Meaning does vmhba1 have the same targets with the same path and caonical path between both hosts? If not, this is where the problem is. The LUNs aren't being zoned identically, somehow.

PS - I am not a SAN admin, so more proper terminology to represent what I'm trying to say could be used, but I do not know how to communicate it Smiley Happy

depping
Leadership
Leadership

Fred is correct:

Create a VMFS volume on the LUN via Server1

Open the Storage Adapters section on Server2 and press "rescan"

Go to the Storage section on Server2 and now you should see the VMFS volume you created on Server1

Duncan

My virtualisation blog:

0 Kudos
hanslad
Contributor
Contributor

Fredpeterson,

It seems to me when I check the Switches that the zoning is the same, but the path and the canonical path is not the same.

Esx1 is connected to two virtual disks on the SAN, ESX2 is only connected to one virtual disk.

See the attached document.

One thing: I have not assigned both virtual disks to ESX 2 in the navisphere tool (AX150).

Is that neccessary to get the right path on host ESX2?

The same disk have different LUN id on the two servers.

0 Kudos
FredPeterson
Expert
Expert

It needs to be the same vmhbaX:Y:Z path across all hosts that need to share the VMFS.

I did a quick bit of documentation reading and came across page some info on Clariion AX100 systems that seems relevant. http://www.vmware.com/pdf/vi3_301_201_san_cfg.pdf page 114 "To resolve issues with invisible LUNs on certain arrays"

While not exactly the same, since you see the LUN, the VMFS is not presenting because it is not the same LUN ID. I found this thread: http://communities.vmware.com/thread/110515 that states the LUN ID needs to be identical across all hosts, but not necessarily the rest of the vmhbaX:Y:Z path.

hanslad
Contributor
Contributor

FredPeterson

The problem was, as you stated, that the drives had different LUN ids on the Hosts.

On AX150 the solution is to assign the disk IN SAME ORDER to both hosts through Navisphere.

Thank you for very helpful replies!

0 Kudos