How can we create Vdisks from same Controller(Say Controller A). I dont see any option to choose when creating Vdisk in CV!
I am creating a DR group and reading instructions from the manual says :
"A DR group can contain virtual disks from multiple disk groups, but all DR group member virtual disks must be in the same array and must be preferred to the same controller on the array"
Can any one explain? your help will be appreciated
Thanks
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DR member virtual disks must be preferred to the same controller on the array " and "all members of a DR group must share a preferred controller, therefore load balancing a single application with all of its virtual disks in a single DR group (as required) across multiple controllers, is not possible" from the above statements . Can u please explain ?
I just checked under presentation tab , it is automatically selected Managing controllers for vdisks (some as controller A and some other as Controller B) I dont see any option to select the controllers !
abstract: All LUNs in a DR group fail over together, share a log and preserve write order within the group. Because one controller manages a group of LUNs, EVA firmware XCS 6.1 (and up) disables implicit LUN transitions for all DR group members.
Mixing Implicit LUN transition (ILT) together with a large DR group can be a recipe for disaster. Imagine if the array detects too much proxy reads on a LUN in the group. The array will evoke a ILT. Because they form a group, all members are transitioned together. So far so good, but you can bet on it that a new proxy read situation appears, due to the multiple hosts communicating with the disks. This will evoke another Implicit LUN transition. And now we are back where we started. Enabling Implicit LUN transition can create some sort of bouncing group of LUNs between controllers
if we are not speaking on the CA, then you can set NONE or all variants of SET PREFERRED PATH TO CONTROLLER A or B (failover only, failover and failback,...) to each VDISK individualy during the VDISK presentation
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