Expanding a SAN LUN on VI3?

[nordsj]

I can expand a LUN on my IBM DS4800, for example its 150GB, can I take it to 500GB Does ESX 3.01 support this or do I need to create a whole new LUN and present this storage to my server as another additional LUN?

If 3.01 supports the LUN growth, do I need to modify anything?

[sbeaver · Accepted solution]

You need to present another LUN you can not growth VMFS partitions

[MR-T]

As Steve says, you'll need to add an additional LUN to make this happen. Once you've presented the LUN to the host, go into configuration, storage and select add extent.

However, I think best practice would be create a new large LUN, migrate the machines from the smaller LUN and then delete this.

This was more of an issue in ESX 2.5.x where you'd lose everything if part of the extent failed, but ESX3 has journaling to prevent this. I'm just old school.

[nordsj]

Thanks for responding folks, I did not know if it was supported in VI3 yet.

[SimonStrutt]

You don't need to provide an additional LUN to expand on space with VI3.

You can just increase the size of the existing LUN on the SAN, then rescan it. VI picks up the increased size, you can then add a new extent to it (ignore the warning about destroying existing data - this refers to data on the space you're about to create a new extent on, not your existing extents) and your job is done. This may not be best practice, but it does work.

[chouse]

Will ESX take advantage of the new free space or just merely report it? Can you create VMDKs that take up the new free space? Other posts seem to say you won't be able to use the space even though the datastore shows it's available, or most everyone says you can't grow the VMFS to take advantage of new free space on a LUN.

[amit40]

Maximun four Extents possible

It is not recommended to expand the VMFS partition but it is still possible to extend the LUN in the normal process from the storage client .