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fercho74
Contributor
Contributor

ESX server does not see formatted storage

Hello all,

I have a newly built ESX 3 server. The server does not see the formatted disks under storage. The server can see the storage when I go to "Storage (SCSI, SAN, and NFS)" and choose "Add Storage". But doing this wants to format the disks. These disks were already formatted by another ESX3 server and have data on them. Any ideas?

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27 Replies
de8o
Enthusiast
Enthusiast

More than likely what has happened is that you presented disks to two or more ESX servers. You then created the vmfs volumes using one server. On the other server it still thinks that the disks have no vmfs volumes.

You'll be glad to know that there is a quick fix. Rescan for VMFS volumes on the server with the issues.

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fercho74
Contributor
Contributor

Thanks for the suggestion. I have already tried to rescan under the storage adaptors and refresh under the storage settings....no luck.

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admin
Immortal
Immortal

I don't think this is a known issue, would make sense to contact VMware support. BTW, can you copy paste the VMkernel log that gets generated in response to the rescan ? It can be found in /var/log/vmkernel.

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de8o
Enthusiast
Enthusiast

Can you do an 'fdisk -l' on the /dev/sd device to see what type of partiton the ESX server is seeing.

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sheetsb
Enthusiast
Enthusiast

I just had the same problem and the host thought the luns were "snapshot" luns. I know this doesn't make sense but I set under Configuration/Advanced Settings/LVM/EnableVolumeResignature to 1 to find them.

Bill S.

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fercho74
Contributor
Contributor

I just tried your suggestion and am now seeing snaps all over the place....

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fercho74
Contributor
Contributor

Additionally, none of the vm's on the disks that show up as snaps are accesible.

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Quotient
Expert
Expert

Perhaps you inadvertently provisioned the LUNs in a different order on each ESX host... To resolve this, ensure that each LUN is presented to each ESX host with the same LUN ID.

You should also back-out the LVM.EnableResignature change you made. This mod should primarily be used only to present snapshot LUNs to your ESX hosts.

If you have a Clariion AX-100 or an IBM ESS you may have difficulty presenting each LUN to each ESX host with the same LUN ID. Do you use either of these storage sub-systems? If so, or you intend on using array based snapshot functionality, you should RTFM the SAN Config Guide, pp108 about the LVM.EnableResignature & LVM.DisallowSnapshotLun options and the related risks.

Hope this helps,

Ben

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fercho74
Contributor
Contributor

The LUN IDs are identical for all hosts. This has been verified by the storage team. I have already set the LVM.EnableResignature to zero and did a rescan...no luck. We do not have a Clariion AX-100, we use Clarion CX500's.

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Quotient
Expert
Expert

Hmmm...

Are you using the Navisphere Agent?

This might help too...[/url]

I'm not all that familiar with the Clariion anymore, only having had exposure to Symms for the last few years.

However, I believe whynotq and mstahl75 have had some decent exposure with the CX of late... Guys?

Regs,

Ben

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mstahl75
Virtuoso
Virtuoso

However, I believe whynotq and mstahl75 have had some decent exposure with the CX of late... Guys?[/i]

I am not the droid you are looking for Smiley Wink

My help with SAN issues is very basic and we don't use that hardware so I'm not much help here :smileygrin:

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abilobrk
VMware Employee
VMware Employee

For both ESX servers do this:

1. Under "Configuration" Click on "Advanced Settings"

2. Select "LVM"

3. for LVM.DisallowSnapshotLun change the value from 1 to 0 then hit "OK"

4. Rescan the SAN

The existing VMFS volumes should now appear in your datastore listing and mount automatically.

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Quotient
Expert
Expert

LOL :smileygrin:

Just calling on the fellow knights - although @ 1261 points, I don't think you'll be with us for long...

Oh well, perhaps the Paul "bot" can help... Smiley Wink

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Quotient
Expert
Expert

LVM.DisallowSnapshotLun change the value from 1 to 0

This will probably work, but fercho, just be aware of the risks as per the SAN Config Guide...

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abilobrk
VMware Employee
VMware Employee

"

I just had the same problem and the host thought the luns were "snapshot" luns. I know this doesn't make sense but I set under Configuration/Advanced Settings/LVM/EnableVolumeResignature to 1 to find them.

"

It's not a good idea to do this unless the LUN is a actually snapshot lun. ESX will detect a LUN as a snapshot if a LUN exists in two separate "Storage Groups" and presented to multiple ESX hosts in this fashion. While resignaturing will work, the solution isn't desirable as all ESX hosts in the environment will continue to detect snapshot luns each time you rescan the SAN and repeatedly resignature the LUNs. You will notice the volume name change from snap001xxxxxx to snap002xxxx and so on indefinitely.

To resolve this issue either set LVM.DisallowSnapshotLun to 0 in the advanced settings or Present your LUNs from a single "Storage Group" across your ESX hosts.

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mbar
Contributor
Contributor

Hi,

I have a situation where I have taken a hardware snapshot of a lun. EnableResignature is set to 1, and quite rightly, after a rescan, I do see the new volume as - snap-nnnnnnnn-<old-vol>.

My question is - Is it possible for me to tell the ESX server - what name should be given to the newly discovered volume?

TIA,

mbar

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admin
Immortal
Immortal

What Quotient says is correct, and might I add that your storage team is wrong. They must have misconfigured the LUNs with different lun numbers. Ask them about LUN numbers and not LUN IDs. These terms mean different things in storage land. The LUN numbers should match.

SAN config guide pg 109. Also, you do not/should not need to play change LVM.* values. This is for snapshot setups only, and should not be used as a hack around incorrect SAN setups.

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nkrick
Enthusiast
Enthusiast

I am experiencing a similar problem. I have 12 ESX hosts and 9 SAN LUNs. 1 Server can only see the VMFS volumes on 6 LUNs. If I click "Add Storage" I can see 3 LUNs with no available space. If I go to Advanced Settings and change "LVM.DisallowSnapshotLun" to 0, I can see all 9 VMFS volumes. I have an EMC CX500 SAN, and I am not using any snapshots. Currently, all 12 hosts and 9 LUNs are in the same storage group. The hosts see the same LUN numbers/id's for all 9 LUNs.

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EnsignA
Hot Shot
Hot Shot

Be sure all of the ESX servers are in the same Storage Group in Navisphere. We had to change from separate storage groups to a single one under 2.5.x when we upgraded to 3.0. Reference Doc ID: 6482648

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