HPE EVA Storage

EVA4400 Won't present vdisks to VMware.

 
Don Krause
Occasional Contributor

EVA4400 Won't present vdisks to VMware.

We're currently installing / testing our first SAN, an EVA4400.

Fortunately, there's no production data on it yet, and we've run into a strange problem. We currently have 7 vDisks presented to both of our vmware hosts.

Upon creation of the 8th vDisk all attempts to present it fail. (I CAN present it to the Command VIew windows box)

I unpresented a couple of the original 7 vDisks, but I can NOT re present them to the VMware boxes.

(The only error just says "Operation failed! The virtual disk could not be presented to a host")

We've rebooted the VMware hosts, and we're getting ready to un init the SAN but there must be something I'm overlooking.

Suggestions?
6 REPLIES 6
Don Krause
Occasional Contributor

Re: EVA4400 Won't present vdisks to VMware.

Interestingly, it seems to be a "phantom lun" issue.

In what is probably a bug, we've twice created a lun that can be seen by the host computers, that the SAN and it's software does NOT see.

The first time, this phantom lun was created by HP personal when they were here installing the EVA. We had to uninitialize the SAN to get rid of the phantom lun.

I then managed to recreate the phantom lun, when I created a new vDisk, and tried to present it to my 2 vmware hosts at the same time the vDisk was being created. (Yes, that's an option right on the vDisk page..)

I received an error that the lun could not be presented because it didn't exist yet, when I clicked OK, the next popup said the the deletion was successful. (I did NOT have the opportunity to delete the LUN, it just did it for me.)

This leaves a phantom LUN, that is visible to the vmware hosts, but the SAN refuses to acknowledge its existence.

Of course, if you actually try to write to or read from that LUN, bam, everything crashes hard.

So, in my case, that phantom lun is visible to the vmware hosts as lun 5. When I try to present a new lun, the SAN software tries to use lun 5, and the presentation fails. If I select any other unused lun id, the presentation works.

So my real issue is how to delete the phantom lun. Yes, I can (and probably will) uninitialize the SAN, but once it's in production, that wouldn't be a valid option.

Does anybody know how to get rid of a LUN that the SAN refuses to admit exists?

Niels Vejrup Pedersen
Respected Contributor

Re: EVA4400 Won't present vdisks to VMware.

Hello,

Can you please supply

Command View version

EVA XCS Code version

Command View Licenses

Regards
Víctor Cespón
Honored Contributor

Re: EVA4400 Won't present vdisks to VMware.

I then managed to recreate the phantom lun, when I created a new vDisk, and tried to present it to my 2 vmware hosts at the same time the vDisk was being created. (Yes, that's an option right on the vDisk page..)

----------------------------------------

Don't do that with a Command View version below 9.1, it's a known problem

Create the vdisk, wait for it to appear on Command View, the present it to the hosts.

Sorry, the advisory is not public, so I cannot post a link here.
JoyBag_1
Frequent Advisor

Re: EVA4400 Won't present vdisks to VMware.

We have a similar issue, but this time caused by a failure of a ZDB backup.

A snapclone was mounted to a backup host to send the data to tape, but the backup job had problems removing the presentation. The job continued, only issuing a minor warning and then proceeded to delete the snapclone from the EVA. As far as command view and SSSU are concerned, the Snapclone has gone, but back on the backup host, the Snapshot is still presented. Infact, we can assign it a drive letter and browse it and create and delete files on it without problem. the only issue arises when we try and run another ZDB backup...it fails to present the new snapclone. We have logged a call with HP to see what they recommend. re-initalising the EVA is not an option! I'm hoping a crontroller resync.
Don Krause
Occasional Contributor

Re: EVA4400 Won't present vdisks to VMware.

From: Niels Vejrup Pedersen

Hello,

Can you please supply

Command View version

EVA XCS Code version

Command View Licenses
----------------------------------

Command View: 9.00.01.090413
Licenses: CV General Unlimited & Business Copy Unlimited
XCS: 09501200
Build: CR13DFlcp
Firmware: mmp-0001-2000-000140

----------------------------------
From: vcespon

Don't do that with a Command View version below 9.1, it's a known problem

Create the vdisk, wait for it to appear on Command View, the present it to the hosts.

Sorry, the advisory is not public, so I cannot post a link here.

----------------------------------

Yeah, I kind of figured that part out..

Question is, is it fixable? Or is a re-initialization my only option?

Thanks,
=Don=
Víctor Cespón
Honored Contributor

Re: EVA4400 Won't present vdisks to VMware.

Don, I have seen only three cases, which is little statistic, but in two we could delete the phantom vdisk using Command View 9.1. In the other one we needed to extract the MLD data and send it to engineering to be cleaned manually.

Command View 9.1 has been modified to ignore corrupt parts of the metadata. Until now a single invalid character on a vdisk name or comments would crash Command View service when trying to read that part of the metadata.