eva5000

[Bob Brason]

Hi,
I would like to know how to locate a disk or vdisk to a particular loop
thanks in advance

mo

[IBaltay]

Hi,
the physical disk locate function is available via the CommandView/disk group/grouped disks/disk or Hardware/Enclosure/disk options...

[Uwe Zessin]

The loop name is shown on the physical disk drive's properties pages together with the disk drive enclosure ID. You then need to find out how the EVA is cabled to identify the loop.

(EVAs are sometimes cabled in non-standard ways... For exampe, I've seen a case where the bottom terminator was used to make room for a new drive enclosure or the top/bottom terminators were swapped - fortunately, I could catch the errors before the systems went into real use.)


A vdisk is spread across all physical disk drives of a disk group and a disk group usually spreads both loop pairs. As suggested, a LOCATE on the disk group gives an interesting insight into how those disk drives are spread...

[Timothy Cusson]

Just curious, why do want to know this?

The EVA5000 has four loops, loop 1a and loop 1b for the drive enclosures below the controllers, and loop 2a and loop 2b for drives above the controllers.

Based on standard proper backend cabling...

Every disk drive is connected to an A loop and a B loop.

Every disk drive is connected to either the lower loop 1 AB or the upper loop 2 AB but not to both loops upper and lower.

[Bob Brason]

Hi Tim,
the answer to your question we had a strange fault where we think the suspect disk is on loop 2a however no faulty disks were shown or displaying any errors

mo

[Víctor Cespón]

That's better seen in the Contoller event log, and capturing the EVA configuration with an SSSU script.
Each disk is connected to both loops, but only one is active at a time, so in an enclosure some disks talk to the controllers though one loop and some though the other.
This can make "missing data" "transfer fail" or "SCSI parity error" events appear on some disks and not on others, but always refer to the same loop.