Why Aren't All LUNs Accessible to Every ESX Host

[Butcha]

Hello guys,

I have one issue that has 2 slightly different presentations. First of all, I have 6 ESX 3.0 hosts all sharing over 40 LUNs being controlled by and IBM DS4800 controller. The first issue is that some of the luns are not visible to some hosts when looking at a host-by-host LUN listing via Virtual Center. This is the case even after rescanning the bus for each hba via Virtual Center.

The second variation of this issue is some cases where the LUN in question will be shown in the LUN listing for a particular host. However, if one attempts to navigate to that LUN via the CLI of host, the task fails.

Can anyone help me prevent my pending mental breakdown over this problem, please?

[MR-T]

Usually these types of things are related to zoning issues.

Are any of your hosts able to see all 40 LUNS without issue?

[Rumple]

You need to also make sure the zoning presents the same LUN ID to each host or else you will end up with real issues.

[Texiwill]

Hello,

Most issues with SANs are actually in the way things are zoned and presented. You may zone things to go through different patchs and present things to ESX from the SAN.

Verify your zoning but also verify your presentation is presenting the same LUN as the same LUN ID to every ESX Server AND that there is no special Type or other settings required for ESX and this SAN.

Best regards,

Edward

[mapic]

Hello,

I had the same issue with the DS4800.

To make the LUN visible to all ESX Servers you have to change the following setting:

Configuration Advanced Settings LVM

Set DisallowSnapshotLUN to 0

Repeat this step for every ESX Server.

• Rescan the LUNs on every ESX Server by selecting “Configuration” “Storage

Adapters”. Right-Click on every adapter belonging to the HBA Adapter and select

“Rescan”.

Repeat this step for every ESX Server.

• Now the LUN should be visible on all ESX Server.