Cannot migrate VM with VMotion, virtual disk is not accessible

[zinovik]

Hello.

I'm trying to setup VMotion for my ESX cluster. I have two Dell PowerEdge 1950 both

running ESX 3.5 with vCenter 2.5 (it is installed in VM). I mounted NFS datastore to

both servers from NetApp FAS 3020c. Server are directly connected to NetApp.

vmkping can successfully reach NetApp filer on both hosts. Network label for

VMotion vSwitch is 'NetApp VMotion' on both hosts, 'Enable VMotion: yes' is set on

both hosts. When i try to vMigrate i get an error that:

Unable to migrate from esx1 to esx2: Virtual disk 'Hard Disk 1' is not accessible

on the host: Unable to access file.

vm/vm.vmdk

When i log to host directly i can reach vmdk file. On both hosts. I thought

that datastore have to be named identically, but when i try to rename datastore

on one host with name from another host vCenter says that 'The name 'vmdk'

already exists.

[zinovik]

I solved my problem.

Here is how vmware works with file systems.

When ESX host attaches file system it create an

universally unique identifier for it or UUID for short.

I assume that it calculates UUID like this:

uuid = hash("hostname or IP addr" + name);

When servers are connected directly to NetApp filer

each server mount same NFS export from filer, but

each export is attached it from different IP address. So

i get different UUID for the same remote NFS export

for each ESX host. I suppose that this thing interferes

datastore naming and it is named like "datastore (#)".

Then i added line to /etc/hosts on both ESX servers:

\[root@esx1 ~\] cat "192.168.1.11 fas1" >> /etc/hosts

\[root@esx2 ~\] cat "192.168.1.12 fas1" >> /etc/hosts

Then i mounted remote NFS exports and discovered that

UUID for this datastore was same on both esx servers.

vMotion still does not work (Virtual hard disk is not

accessible) and i think i know why. Just because computers

use IP addresses for communication. When vMotion starts

it resolves fas1 on both servers and get different IP for each

server and i suppose that this prevents vMotion to function,

e.g. ESX1 tries to access 192.168.1.12 through network and

fails.

So i'm to tired to resolve this stuff.

I attached my ESX hosts back to cisco switch 2960G.

Then i attached remote NFS exports with same name for

datastore. vMotion work, everybody happy.

P.S. Can someone test this on ESX 4?