ESXI Remote console & Disk Alignment

[scott_dugan]

Hi Guys and Gals,

we are currently implementing our fist Netapp Vseries solution and i'm kinda a noob. So Sorry if i seem a bit thick.

I have presented some disk stores to our ESX environment and now we are looking to migrate some of oour VM's to this store. We currently have an ESXI cluster running accross our DC's. I have had a look at the disk components of our VM's and they appear to be out of alignment. Our environment is win2k3 and 2k8. The 2k8 VM's should be fine but the 2k3 VM's need to be aligned. I have downloaded the ESX Host Utilities 5.1 as netapp claim there are problems with 5.2.

Can anyone point me in the right direction of how i run mbralign from remote to a vmdk file?

Thanks in Advance for all you help.

[jeredarassier]

Are you using NFS datastores? Or block level?

If NFS you can run the MBR align tool from any linux helper VM VM fairly easily

There is a nice writeup here

http://blogs.netapp.com/storage_nuts_n_bolts/2009/10/esxi---mbrscanmbralign.html

[scott_dugan]

Jeredarassier,

Thanks for the quick reply to my post. We are using block level. Your right it's a nice write up on mbralign and mbrscan.

Unfortunitaly it does not solve my problem.

[jeredarassier · Accepted solution]

The mbrscan and mbralign tools need to be installed on the service console of an ESX machine (not esxi as it does not have a service console) or a helper VM if it can access the storage.

As you are running block level storage a helper VM is not useful to you as it cannot access your storage (Even if you passed it the LUN's it would not know what to do with VMFS)

Looking at other threads like this http://communities.vmware.com/thread/263820;jsessionid=95EB63CD3D05C808AAE0B10DB5686502?tstart=0 some people are putting in an ESX box temporarily and attaching it to their storage to perform the alignment work.

Other than that I have not been able to find a work around for block level storage and ESXI other than a temporary full blown ESX installation.

What you COULD do if your licensed for NFS on your filer, even if you don’t want to use it for your production storage protocol is make a temporary NFS volume, storage vmotion the target VM’s over to it (thereby making it accessible to a helper VM) align it and storage vmotion it back.

Other than that I am not sure if any of the other 3^rd party alignment tools out there can interface with an ESXI box.

[scott_dugan]

Sorry Jeredarassier,

I missed your post in haste to try and solve this problem. It looks like you have answered the question. I don't seem to be able to find another way of making this work. I have searched the net for majority of the day looking for a solution here. We might just have to bite the bullet and connect a full blown ESX os to our environment

[rjparker1]

Jered Rassier wrote:
The mbrscan and mbralign tools need to be installed on the service console of an ESX machine (not esxi as it does not have a service console) or a helper VM if it can access the storage.
As you are running block level storage a helper VM is not useful to you as it cannot access your storage (Even if you passed it the LUN's it would not know what to do with VMFS)

OK then, VSphere 5.0 will *ONLY* be ESX5i, no service console.  so how are we going to align disks if there is no service console?!?

[dandillharsch]

What kind of annoys me is that it's right there on the download page for the tool that is built in to VSC 2.0.1 however it says it doesn't work in the VSC manual.

Page 38 of the VSC 2.0.1 install and admin guide: "The MBR tools cannot run on ESXi hosts."

Am I missing something, did it work on esxi at some point or is the tools page in the VSC just blatantly wrong?

[dandillharsch]

What kind of annoys me is that it's right there on the download page for the tool that is built in to VSC 2.0.1 however it says it doesn't work in the VSC manual.

Page 38 of the VSC 2.0.1 install and admin guide: "The MBR tools cannot run on ESXi hosts."

Am I missing something, did it work on esxi at some point or is the tools page in the VSC just blatantly wrong?

[dominicb]

Hi Scott,

This is covered in the install and admin guide for VSC 2.01

http://now.netapp.com/NOW/knowledge/docs/hba/vsc/relvsc201/pdfs/install.pdf

Also covered in the ESX Host Utilities Kit install and admin guide.

http://now.netapp.com/NOW/knowledge/docs/hba/esx/esxhu51/pdfs/install.pdf

As you are using ESXI I think you should be referrring to the VSC guide rather than host utils.

Cheers

Dominic

P.S. Make sure you have a backup before you run it.

[scott_dugan]

Hi Dominicb

Thanks for the assistance. My question is still how do i run the mbrtools on ESXI when the VM has to be shut down to run the tools?

Checking VMDK partition alignment with mbrscan
You can use the mbrscan tool included with Virtual Storage Console to check VMDK partition
alignment.
About this task
The mbrscan tool is effective on -flat.vmdk and fixed .vhd files that are partitioned using a master
boot record (MBR) partition table.
Steps
1. Shut down the virtual machine.
If you do not want to shut down the VM, take either a Data ONTAP Snapshot copy of the volume
containing the Datastore LUN or NFS Datastore, or take a VMware snapshot of the VM in
question, and then run mbrscan against the copy.
2. On the ESX host console, change to the directory where mbrscan is installed.
3. Enter the following command on the ESX host console:
./mbrscan { --all | filename }
The --all option scans all -flat.vmdk files.
filename specifies the name of a single file to scan.
The command displays whether the VMDK partition is correctly aligned.

Can this be run from the Virtual Center Server? Maybe i am getting confused here. "Most Likelly"

[dominicb]

"shutdown the virtual machine" my understanding is to shutdown the vm you are going to run the mbr tool against, not the vm that virtual center is running on.

Is that what you mean?

You can also check VM alignment from a Windows 2003 host without shutting it down by looking at:

Start -> All Programs -> Accessories -> System Tools -> System Information

Then expand Components section then expand Storage section and select "Disks"

Look in the list of settings in right pane for Partition Starting Offset. If this number is divisible by 4096 then you are aligned. If it is not then you are misaligned.

More details in here, page 80:

http://media.netapp.com/documents/tr-3749.pdf

[scott_dugan]

Thanks Again Doninicb

I have already verified that the VM in question is out of sink. My issue is that the Environment is ESXI, You can't install the ESX host utilitieson ESXI so how can i run the mdrscan tool?

[dominicb]

Hi Scott,

Referencig this doco:

http://media.netapp.com/documents/tr-3747.pdf

Best Practices for File System Alignment in Virtual Environments

FIXING ALIGNMENT FOR MISALIGNED VMS HOSTED ON VMWARE ESXI
In order to leverage the NetApp mbralign tool for correcting the file system partition alignment for misaligned VMs hosted on ESXi hosts, NetApp recommends leveraging a standby VMware ESX host and using a supported version of the mbralign tool to fix the VM alignment issues. This standby VMware ESX host should have access to the NFS/VMFS datastores hosting the misaligned VMs. Also, it is not required that this ESX host be part of the HA/DRS cluster hosting production VMs.

I think you will have to install a temp ESX host to use the mbralign tool.

Cheers

Dominic

[scott_dugan]

Guys thanks to all of you for your assistance.

It looks like that's what we are going to haveto do. We will setup another ESX box for use to align our disks.

P.S. hav any of you used "Gparted"

[jbaginski]

We are going through the same exercise. It seems better for us to mount an NFS datastore and export to a Linux host. storage VMotion the misaligned LUN into the NFS datastore and perform the alignment. Then storage VMotion the Datastore back. By going this route we avoid the bottlenecks of the service console.

[scott_dugan]

thanks johnathan,

kinda wish i has an NFS license right about now.

[PL_DGARCIA]

Yes, I'm using GParted to re-align the NTFS partitions on my Windows guest machines and it is working well for me. It will not work on Dynamic disks, the disk must be a simple/basic disk in order for GParted to re-align it.

I originally tried using mbralign from a CentOS host on an NFS Datastore but found it much more diffcult to use and ended up with a corrupted VM during my testing. I'm sure it would have worked fine from an ESX host but that wasn't an option for me.

[dandillharsch]

What kind of annoys me is that it's right there on the download page for the tool that is built in to VSC 2.0.1 however it says it doesn't work in the VSC manual.

Page 38 of the VSC 2.0.1 install and admin guide: "The MBR tools cannot run on ESXi hosts."

Am I missing something, did it work on esxi at some point or is the tools page in the VSC just blatantly wrong?