EVA 4400: one or two disk groups?

[Uwe Zessin]

Zoning is not so much used for 'security' - it is for isolation of ports, for example to prevent server FC adapters from talking to each other or receiving unnecessary update information (RSCNs) from the Fibre Channel switches.



Separate fabrics are used to create different failure domains. It will also reduce the number of 'redundant' paths - I beleive it is not really necessary to have 8 paths to an EVA 4400 virtual disk. All these paths will need to be managed by the operating system and in the case of a failure, the OS might waste some time trying many failed paths.


Zones are managed from one switch only and (of course) can span interswitch links [ISLs] - do NOT include those switch ports in the zones.

Yes, it is some work during initial setup, but it allows fine-grained control of access. For example, you can temporarily remove one server from the EVA by changing the zoning -- without making physical changes like unplugging ports.


Use member alias names and be wise when chosing zone/alias names and you even have kind-of 'online documentation'. Since you are using Brocade switches, learn about the "nsaliasshow" command and how it includes member names in the output (I'll put the example in the attachment).

[welldone777]

Thank you, Uwe Zessin.
I have some questions.
As i said, i have 24 disks (146 GB). One disk group.
I create four vdisks (200GB, 400GB, 800GB and 900 GB).
1. Every disk is managed by Controller 1. Can i assign Controller 1 for 200 GB and 400 GB and Controller 2 for 800 GB and 900 GB for balancing? How?

2. I see "Alarm level exceeded" for disk group. "Total 2877 GB" and Alarjavascript:postAnswerSubmit('submit');m Level is 90%. There are 98 GB free space for Vraid5. Security level is Single. What does it mean? Necessary two disks (Single level) are already allocated? Or i need to leave 300 GB free space manually?

[Víctor Cespón]

You can set the preferred controller for each vdisk.

- Controller A Failover Only
- Controller B Failover Only

or set "No preference" and let the multipath software device. The EVA4400 is Active/Active, so both controllers and all 4 paths can be used to access a vdisk.

In the disk group you have two lines:

Disk failure protection = Single reserves the space equivalent to 2 x (biggest disk on the disk group). That space cannot be used to create vdisks and is not taken into account in the disk group total space.

Alarm level: This sets a line on the remaining space, if you fill the disk group above that line, the EVA logs an event and shows a warning on the disk group.

[welldone777]

I set "Controller A Failover Only" and "Controller B Failover Only", but in "Presentation" of every Vdisk is "Managing Controller: Controller 1".
If there are no free space and i get alarm - will i have problems?