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leif_hannusas
Contributor
Contributor

Error when creating vms on NFS,

Hello,

I get the error "Communication with the virtual machine may have been interrupted"[/i] when i try to create vms on my nfs storage; if i try to create vms on my local scsi disk it works fine.

I use Windows Services for Unix 3.5 as NFS storage and i have mounted NFS storage to both esx 3.0 servers.

Any idé whats wrong? Where does esx 3.0 mount it's NFS mountpoint?

Best regards Leif

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Texiwill
Leadership
Leadership

Hello,

FIrst look at your Network configuration. NAS/NFS requires a vmkernel based vSwitch and depending on your netmask it could be picking up the incorrect one. For a while there, mine was on my vMotion network. Which is problematic since it is a private network. I changed my netmasks and all was well. I have a vmkernel based portgroup for iSCSI which is attached to my service console vSwitch (it can be separate but the Service Console must be able to see all iSCSI hosts), a vMotion vmkernel vswitch, and a NAS/NFS vmkernel vswitch. My NFS server resides on its own network shared with the NIC associated with the NAS/NFS vmkernel vswitch.

Once you verify your network configuration and you are connecting using the proper vSwitch (Your NFS and vmkernel logs should help quite a bit). It is time to investigate the activity on the NFS server by looking at its logs.

I could not get SFU to work so I went to a different NFS option that works just fine. I think my network configuration is just a bit odd for SFU.

All data stores appear in /vmfs/volumes on an ESX server including NAS/NFS based ones.

Best regards,

Edward

--
Edward L. Haletky
vExpert XIV: 2009-2023,
VMTN Community Moderator
vSphere Upgrade Saga: https://www.astroarch.com/blogs
GitHub Repo: https://github.com/Texiwill
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leif_hannusas
Contributor
Contributor

Hello,

FIrst look at your Network configuration. NAS/NFS

requires a vmkernel based vSwitch and depending on

your netmask it could be picking up the incorrect

one. For a while there, mine was on my vMotion

network. Which is problematic since it is a private

network. I changed my netmasks and all was well. I

have a vmkernel based portgroup for iSCSI which is

attached to my service console vSwitch (it can be

separate but the Service Console must be able to see

all iSCSI hosts), a vMotion vmkernel vswitch, and a

NAS/NFS vmkernel vswitch. My NFS server resides on

its own network shared with the NIC associated with

the NAS/NFS vmkernel vswitch.

Once you verify your network configuration and you

are connecting using the proper vSwitch (Your NFS and

vmkernel logs should help quite a bit). It is time to

investigate the activity on the NFS server by looking

at its logs.

I could not get SFU to work so I went to a different

NFS option that works just fine. I think my network

configuration is just a bit odd for SFU.

All data stores appear in /vmfs/volumes on an ESX

server including NAS/NFS based ones.

Best regards,

Edward

Thank's for the good info; ill check it out because i use a privet network as well as you describe with VMotion.

Ill will check /vmfs/volumes store for reda and write access if that could be the problem as well.

Must VMkernel vSwitch for NFS reside on another subnet the VMotion to work?

Best regards Leif

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leif_hannusas
Contributor
Contributor

Hello again,

now i have work on it and i have found a really funny error? if i create vms virtual disk on selecting lest say 2 GB an i type it in i get Unable to access file the if i make the same thing again but select 2000 MB virtual disk it works until i get up to lets say 3000 MB the i get the same error.

is there someone familiar with this error or could it be that i have slow nics that cant create .vmks fast enoff

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Texiwill
Leadership
Leadership

Hello,

vMotion and NAS vmkernel vswitches do not need to reside on a separate subnet for NAS/NFS to work, but you WILL want them on different subnets as you do not want an NFS read/write to interfere with vMotion in any way.

When you create a VM on a NAS partition you should use a 2GBSparse format file (oldstyle workstation 4). 2GB sparse will create a VMDK with multiple 2GB files (for VMDKs greater than 2 GBs). THe reason for this is that the OS upon which you are creating the VM does not understand > 2GB files. I think that is really your problem. SFU for Windows, has all the issues that windows has with files > 2GBs and may have its own issues. I think you will want a different NFS server.

Best regards,

Edward

--
Edward L. Haletky
vExpert XIV: 2009-2023,
VMTN Community Moderator
vSphere Upgrade Saga: https://www.astroarch.com/blogs
GitHub Repo: https://github.com/Texiwill
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leif_hannusas
Contributor
Contributor

Hello,

vMotion and NAS vmkernel vswitches do not need to

reside on a separate subnet for NAS/NFS to work, but

you WILL want them on different subnets as you do not

want an NFS read/write to interfere with vMotion in

any way.

When you create a VM on a NAS partition you should

use a 2GBSparse format file (oldstyle workstation 4).

2GB sparse will create a VMDK with multiple 2GB files

(for VMDKs greater than 2 GBs). THe reason for this

is that the OS upon which you are creating the VM

does not understand > 2GB files. I think that is

really your problem. SFU for Windows, has all the

issues that windows has with files > 2GBs and may

have its own issues. I think you will want a

different NFS server.

Best regards,

Edward

Hello,

Thanks for the info; i change to NAS/NFS storage to FreeNAS and it's on the FreeNAS i get this problem on the SFU couldn't i even create a vm at all; but ill try your tip to morrow to break the virtual disk in to 2 GB space format.

Thanks for the info // Leif

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leif_hannusas
Contributor
Contributor

Hello

Where can i sett the 2GBSparse format file is it in VI Client or on my NFS server?

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Texiwill
Leadership
Leadership

Hello,

YOu can use the following to create a 10GB 2gbsparse VMDK. Where NFSMOUNT is your NFSMOUNT point in /vmfs/volumes.

vmkfstools -c 10G -d 2gbsparse /vmfs/volumes/NFSMOUNT/VMName/VMName.vmdk

THere is no way to create the VMDK this way when using the VI Client. If this works then SFU is imposing a 2GB filesize limit. The NFS server I use does not have that limit. I use a commercial program from Lab-NC Ltd. named WinaXe. It is also a X server amoungst otherthings. YOu could also use the NFS server that is part of cygwin as well.

Best regards,

Edward

--
Edward L. Haletky
vExpert XIV: 2009-2023,
VMTN Community Moderator
vSphere Upgrade Saga: https://www.astroarch.com/blogs
GitHub Repo: https://github.com/Texiwill
leif_hannusas
Contributor
Contributor

Hi,

I found my problem, i used the wrong filesystem format.

Thanks för the help Texiwill Smiley Wink

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