Disk Enclosures
cancel
Showing results for 
Search instead for 
Did you mean: 

EVA LUN ALLOCATION

pkumar97
Frequent Advisor

EVA LUN ALLOCATION

am attaching some screenshots with this post
Please check the details and suggest me how we can allocate these disk via controller b , becasue it is currently through controller A , Also pelase tell me how we can change
Host LUN SCSI Reservation
AGIMX1 6 None
AGIMX2 6 None
scsci reservation becasue it is currently none it should be like Regular .
9 REPLIES
pkumar97
Frequent Advisor

Re: EVA LUN ALLOCATION

Am attaching the sheet
Santhosh D
Valued Contributor

Re: EVA LUN ALLOCATION

Hi,

First of all, please let us know what HSV Controller is it

Because in early generations like EVA 3k and 5k, we had this utility called SCSI reservation which was in use. For example, if you have a VDISK where Controller A is the Master, then the Host has to access the ownership from the Master always and then release it.

But in new generations, we dont have that function any more, any Host wich is presented to that LUN can access that VDISK wothout changing the Ownership.

This technology applies when Master Controller fails also. The Slave controller will take over the ownership.
pkumar97
Frequent Advisor

Re: EVA LUN ALLOCATION

currenty we are using EVA4000
pkumar97
Frequent Advisor

Re: EVA LUN ALLOCATION

can any one please have a look on this
Uwe Zessin
Honored Contributor

Re: EVA LUN ALLOCATION

> this utility called SCSI reservation which was in use.

SCSI reservations have *NOTHING* to do with the internal virtual disk management ownership of a controller. They are used by some host operating systems (Windows Clusters, Tru64 Unix Clusters, VMware ESX server, sometimes IBM AIX) to serialize access to a disk.
.
Víctor Cespón
Honored Contributor

Re: EVA LUN ALLOCATION

You currently have the vdisk Preferred path/mode set to "No preference", so the control is from the multipath software on the server.

The vdisk will stay associated to controller A until the multipath software changes it, or more than 60% reads come from controller B and the EVA changes it.

AGIMX1 and AGIMX2 are the servers to which this vidks is presented.

Regarding "SCSI Reservation", why do you need to change it? Where's documented?
pkumar97
Frequent Advisor

Re: EVA LUN ALLOCATION

vcespon ,
Am asking whether we need to do anything with that i mean regarding " scsi reservation " . I just want to cross check with you guys anything wrong with the allocation .

Am attaching the vdisk details once again . Please verify this . if anything wrong please suggest how we have to rectify
pkumar97
Frequent Advisor

Re: EVA LUN ALLOCATION

attached sheet
Dennis L W Thury
Frequent Advisor

Re: EVA LUN ALLOCATION

I assume you have MPIO installed on the 2 servers (AGIMX1 & AGIMX2). I further assume these 2 servers are clustered.

You could set the preferred path for this disk from within CV by selected the desired value for "Preferred path/Mode" under the presentation path. But that's not what I'd do.

I'd run MPIO CLI on each server, and issue the command sequence:
"hpdsm devices"

"hpdsm device=n paths"

"hpdsm device=n path=m"

Notice that this will disable any load-balancing policy on that disk, which I don't think is a good idea.

Instead, I'd set an appropriate load balancing policy (I tend to use SQST, meaning use the path that has the shortest queue based on the service time of that path. I'd also be sure ALB is enabled.

Hope this helps,