topic Configuration Disk Group in a EVA 4000 in HPE EVA Storage

Configuration Disk Group in a EVA 4000

Jorge Arquillo Mantas — Mon, 28 Sep 2009 15:25:52 GMT

I have an disk group with 20 discs 146,8 GB. Fibre Channel

I buy 8 discs 300 GB Fibre Channel more.

Is better add the new 8 discs of 300 GB an existing disc group 146 GB or create a new disc group ???

A lot of thanks.

Regards.

Re: Configuration Disk Group in a EVA 4000

Uwe Zessin — Mon, 28 Sep 2009 18:22:37 GMT

Create a new disk group. I don't beleive that the EVA behaviour is predictable when mixing disks. E.g. what happens when disks fail and new ones get added to the group: I fear that the EVA can 'marry' large and small disks which can cause a loss of capacity over time.

Re: Configuration Disk Group in a EVA 4000

Johan Guldmyr — Tue, 29 Sep 2009 09:20:05 GMT

It can also cause the newer/larger disks to be overused. I would recommend a new DG as well.

Re: Configuration Disk Group in a EVA 4000

Uwe Zessin — Tue, 29 Sep 2009 09:30:18 GMT

I think I understand what you wanted to say:

A disk (pair) is filled with the same percent level like a disk group. If a disk group is filled 50%, then a 146GB disk is filled 73GB and a 300GB disk is filled 150GB (I ignore some special cases). So there is a good chance that a larger disk will receive more I/Os.

Re: Configuration Disk Group in a EVA 4000

Jorge Arquillo Mantas — Tue, 29 Sep 2009 11:05:13 GMT

A lot of thanks.

I will create a new disk group witch eight disk 300 GB FC.