A single LUN among from a group disappeared following the ESXI host restart

[mariolos]

A single LUN among from a group disappeared following the ESXI host restart. Neither the host nor the Vcenter can see it.

I have four virtual machines on the LUN  hiden now showing just unknown from VCenter.

Although strange  I see the LUN  available from the list you get when you try to ADD datastore from configuration ==> storage ==> Add Datastore.

I really need to mount the lun without formating since i have those four servers on it.

As an alternative being able to copy the files will do.

thanks

[a_p_]

Welcome to the Community,

issues like this can occur if a LUN is presented to e.g. a Windows host which has "Automount" enabled. Anyway, you may want to take a look at http://kb.vmware.com/kb/1011387 and/or http://kb.vmware.com/kb/1015986 to see whether these articles help to mount the datastore on the host.

André

[mariolos]

That explains the Partision type being MBR ... but still I cound not find a way to put it live. Basically i want to mount it back with out losing any data.

[a_p_]

That doesn't sound good. Was the datastore created using ESXi 5 (with GPT) or with an earlier version of ESXi?

André

[mariolos]

Earlier Version,  version esx4 . How bad is it?

[a_p_]

Earlier Version,  version esx4 . How bad is it?

That's not bad at all. In this case you should be able to access and repair the partition using fdisk. Can you please run fdisk -lu from the command line (or SSH) to see whether this works for the LUN in question and post the output?

André

[mariolos]

this is what i got

/dev/disks # fdisk -lu naa.600508b4000bb6500001c00002b00000

Disk naa.600508b4000bb6500001c00002b00000: 1288.4 GB, 1288490188800 bytes

255 heads, 63 sectors/track, 156650 cylinders, total 2516582400 sectors

Units = sectors of 1 * 512 = 512 bytes

                                Device Boot      Start         End      Blocks  Id System

[a_p_]

Without knowing the reason why the LUN disappeared there's always a risk, so before doing anything you may consider to snapshot or clone the LUN on the storage side if possible.

What you could try is to recreate the partition table following the steps in the ESX 4 section of http://kb.vmware.com/kb/1002281. If it was just the partition table which got lost you should see the datastore again after creating (and aligning!) the VMFS partition.

André