Can ME4024 Jumbo & Host Ports be changed 'online' please?

Question

Hi, we have a ME4024 just in production providing new iSCSI storage for a small vSphere 6.0 environment, as we move from a VNXe with 1Gb/s networking to 10Gb/s, with no outages allowed for.

We need to enable Jumbo Frames shortly, and change Host Port addressing on a port that is currently connected to a host's iSCSI initiator but not active.

I imagine these can be changed without disruption to existing traffic, but the last time I changed a host port address, an unexpected high number of event messages from the ME4024 was generated, which had me worried it could have affected iSCSI production traffic on the other host ports.

I imagine we experienced normal behavior, but I am risk adverse now (!) and so ask for any advise anyone has.

Thank you.

hugovg2 · Accepted Answer

Thanks for that Sam. I can confirm for anyone interested that the link status for _all_ 8 host ports were cycled when I changed the IP address of just 1 of them. We have multiple iSCSI paths configured so there was no loss of storage connection, just unexpected. I expect changing MTU will likewise cycle all ports. Thank you.

DELL-Sam L · Answer

Hello hugovg2,

Here is what we list in the administrator guide under Changing host port settings on page 52.

You can configure controller host-interface settings for ports except for systems with a 4-port SAS controller module. To enable the system to communicate with hosts, you must configure the system's host-interface options.

NOTE: If the current settings are correct, port configuration is optional.

For a system with a 4-port SAS controller module, there are no host-interface options.

IMPORTANT: Changing the fan-out setting will change the logical numbering of controller host ports, which will cause port IDs in mappings between volumes and initiators to be incorrect. Therefore, before changing the fan-out setting, unmap all mappings. After you have changed the fan-out setting and connected the appropriate cables, you can re-create the mappings.

CNC host ports can be configured as a combination of FC or iSCSI ports. FC ports support use of qualified 8 Gbit/s or 16 Gbit/s SFPs. You can set FC ports to auto-negotiate the link speed or to use a specific link speed. iSCSI ports support use of qualified 10 Gbit/s SFPs, or qualified 10 Gbit/s Direct Attach Copper (DAC) cables

Here is the link to the administrator guide. https://topics-cdn.dell.com/pdf/powervault-me4012_administrator-guide_en-us.pdf

Once you have made your changes you will want to reset the host ports. You can find more information about resetting host ports on page 61.

Please let us know if you have any other questions.

PowerVault

Can ME4024 Jumbo & Host Ports be changed "online" please?

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