Reconnecting disk to datastore after RAID array rebuild

[ellore]

Hello,

Yesterday one of our ESX datastore drives died and was replaced. The datastore disk was a part of RAID5 and was rebuilt soon after, but ESX hasn't reconnected the disk to the datastore.

On ESX GUI, I can see the disk and that it still has the data on it, but it is not connected to the datastore.

esxcli storage vmfs extent list:

Mount Point	Volume Name	UUID	Mounted	Type	Size	Free
	datastore2	5795f52e-3d31e7e0-fc5d-5ef3fcdae3d3	false	VMFS-unknown version	0	0

How can I set the mount point of the datastore to the replaced disk? It has a new ID and probably that's why it didn't connect to the DS automatically.

[a_p_]

Welcome to the Community,

The datastore disk was a part of RAID5 and was rebuilt soon after, but ESX hasn't reconnected the disk to the datastore.

A RAID rebuild on a supported RAID controller is transparent for the host OS (ESXi in this case)., and from what you say the RAID rebuild succeeded, so the second part of that sentence is what I don't understand. There's nothing that ESXi has to do with the RAID rebuild, because the RAID controller presents a LUN to it.

Can you please explain this in more detail, and explain in exact steps how the replacement was done, and what type/model of RAID controller you are using?

André

[ellore]

I forgot to mention that the disk is actually from a Synology NAS. Synology itself reported that the disk has been rebuilt and the LUN is all up and running. The rebuild disk is showing up in ESX.

[a_p_]

Then it looks like a configuration issue on the Synology. The replaced disk should not even be presented to the ESXi host, but only the RAID5 LUN.

Since - how I understand it - the replaced disk is now part of the RAID set, but still shown on the ESXi host, you may try to remove/detach the disk object from the ESXi host's inventory.

André

[ellore]

ESXi has been configured to use the Synology's LUN(the RAID5 array). It seems that Synology rebuilt the replaced disk and ESXi reestabilished connection to the RAID5 LUN and that's why it's visible on the ESXi host.

So, currently the Synology LUN is shown on ESXi, but the Datastore itself isn't using the LUN.

Sorry if I explained this too complicated.

[a_p_]

I think I now understood the situation.

In this case please go to the "Command line" section in https://kb.vmware.com/s/article/1011387​ to see whether the datastore shows up as a snapshot LUN, and can be mounted.

André

[ellore]

Hello André!

ESXi reports back that there are no snapshot LUNs. What should I do in this case?

[a_p_]

ESXi reports back that there are no snapshot LUNs. What should I do in this case?

Try to contact continuum​ via Skype.

One more thing you can do is to run the "offset="128 2048"; .... ; done" command line ("Step 1" in https://kb.vmware.com/s/article/2046610) on the ESXi host, and post the output.

André

[ellore]

Hello André!

Here's the output of that command.

/vmfs/devices/disks/naa.60014058a36902ad855ad3655db696db

gpt

130541 255 63 2097152000

1 2048 2097141164 AA31E02A400F11DB9590000C2911D1B8 vmfs 0

Checking offset found at 2048:

0200000 d00d c001

0200004

1400000 f15e 2fab

1400004

0140001d  64 61 74 61 73 74 6f 72  65 32 00 00 00 00 00 00  |datastore2......|

0140002d  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|