How to disable "write cache mirroring" on EVA storage?

[Cho,Hyun(Chris)]

Hello, dear.

As title, Could anyone let me know how to disable "write cache mirroring" on EVA storage.
I think this feature does not same as write back or write through on write cache.
In order to increase almost heavy write performance up about 16%, it will be good.
In this configuration, Of course, I know if one controller fails, systems will be crashed.
Attached files are best practice performance on EVA. see page 13 for "write cache mirroring"

Thanks.

[Uwe Zessin]

In early version it was a selectable item in the GUI. These days it is still available in SSSU, however, when I try it with CV V6.0.2 against an EVA-4000:

E4K> set vdisk "\Virtual Disks\S2\S2-2\ACTIVE" mirrorcache=notmirrored

Error: Error cannot modify object properties. [Unsupported operation for AA mode]
E4K>

Looks like this feature is only available with active/passive EVAs. Maybe it has been removed to simplify the XCS firmware: if the I/O goes to the controller, which does not own the virtual disk, the data must be sent over a mirror-port anyway.

[Víctor Cespón]

Hi, just to confirm, I tried it on two EVA GL, one with firmware 3110 and another with 4100.
In Active/Active mode, it's not possible to disable.
There's the option in Active/Passive mode when creating an vdisk or it can be changed using SSSU.