some random newbie questions

[sean1017]

hello all,

this is my first post and i'm fairly new to VMWare so forgive me if i misspeak or post in the wrong forum.

The basics - I am running VI3 and plan on having two servers in the production enviornment so we can take advantage of vmotion and some of the other cool VI features. We are using a netApp filer for our SAN in the production enviornment.

Our plan is to virtualize all our mission critical servers to make DR a piece of cake (on paper at least ). We will eventually have a ESX server in a DR site as well as an equalogic SAN. We would've liked to have had similar SANs but the budget didn't quite allow for it this year. we will be replicating VMs between production and DR using ESXReplicator software.

Anyway, my questions are the following:

1) What is the best way to move a VM from one LUN to another LUN? the first VM i created i did it on a test LUN and now i want to move it to the production LUN.

2) Along those same lines, my production LUN is now almost filled and I'm nowhere near done P2Ving my servers so I need to increase it. I assume i first increase the LUN on the Netapp side, and then what? how do i get the ESX server to notice the new space? i tried rescanning but it didn't work.

3) re: vmconverter, how does vmconv deal with the inconsistent nature of what it does? in other words, if i hot clone a server, the entire time that it's being cloned the physical server is still working and therefore i assume there will be differences between the virtual clone and the physical server by the time it's done. the few servers i've P2V'd already had DBs stored remotely so i wasn't so worried about this but now i'm about ready to do a DC and an LCS server both with locally stored info.

4) I've read a few threads on this already but can anybody give me a cliff-notes version of whether i should or shouldn't keep my MCSC server for SQL, Exchange, and File Servers? It certainly seems like a pain to keep them and if all we're losing is the ability to do rolling upgrades then i'm probably fine with it. but from my understanding, HA can only deal with hardware issues...if there is a software issue i'm screwed right? or i guess i could go back to a snapshot of when the server was working properly but that could be a transaction log nightmare right?

5) what is the difference between HA and VMotion?

Thanks for your help on any/all of these questions.

Sean

Message was edited by:

sean1017

[oreeh]

Hi, take a seat and a beer

1) there are several ways to do this

\- you can simply "copy" the files over (provided the ESX sees both LUNs)

\- you can do a cold migration from one ESX to another

2) depending on the size of the LUN you better create a new LUN and present it to the ESX hosts.

A rule of thumb: put no more than 10-15 VMs on one LUN (this depends on the workload of the VMs of course)

3) Converter uses "snapshots" and shadow copy for this.

Converting a running SQL server is not a good idea. The same goes for AD servers.

In case of an AD server simply create a new one in a VM.

4) If you need 24x7 uptime you should stick with MSCS.

You can use snapshots / backups instead but as you already said: this can be a nightmare.

HA is only "crash consistent"! If the host fails the VM is simply powered off and powered on on another host

5) vMotion: move a running VM from one host to another host (both ESX hosts need to have access to the same LUN)

HA: in a host failure VM simply restarts the VMs on another host

[esiebert7625]

5) what is the difference between HA and VMotion?

VMotion is moving running VM's from one ESX host to another without any interruption of service. HA is a service that will bring VM's up from a failed ESX host on another ESX host, it is the equivalent of hard powering off a VM on one host and powering it back on another host

4

HA is not true clustering without downtime, MSCS is closer but not it also, see this thread for more info...

http://www.vmware.com/community/thread.jspa?messageID=741291

3

Converter will basically snap the server when hot-cloning, any subsequent changes will be lost. It is not recommended to hot clone sensitive servers like database and exchange servers. See this thread for more info...

Converter snapshot during hot migration - http://www.vmware.com/community/thread.jspa?threadID=87540&messageID=660907

2

You could either create a 2nd LUN and create another VMFS volume or you could extend your present LUN and then click Add Storage (no need to rescan since the server already sees the LUN) and choose a device that has available space on it. To make your existing VMFS volume larger you can use extents but they are not recommended.

1

You can shut the VM down and do a cold migrate if you have VirtualCenter. If not VMware Converter can do this for you or you can use SCP and vmkfstools -i to do this.

Fyi…if you find this post helpful, please award points using the Helpful/Correct buttons.

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Thanks, Eric

Visit my website: http://vmware-land.com

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[zbenga]

another thing to note with HA and DRS is all esx server in the "cluster" need to have the same networking (read vswitches) setup and connected via NIC's to your infrastructure, few people forget this and it bites

eg. ESX1.yourcomp.net has a dmz vswitch setup and ESX2.yourcomp.net don't they when HA happens or DRS you will either not get HA and DRS or if you force it in the options it will be pointless as no connection to it will be available

[sean1017]

\*finishing my last sip of beer...*

thank you all for your replies. they are quite helpful and probably saved me a couple hours of RTFM. actually i have been reading the manuals but there is a lot of material there and not much time.

[sean1017]

so if i want to just copy from one LUN to the other, what is the best method for doing that? do i have to do it from the CLI? When i browse the datastore from VI i can only delete.

Thanks

[oreeh · Accepted solution]

Yes you have to use the CLI using the vmkfstools command.

The datastore browser is just that - a browser (with added delete functionality).

[tmcd35]

Wouldn't Veem's FastSCP program be the easiest tool to copy a VM from one LUN to another?

[esiebert7625]

Yes FastSCP works great for this for going from one ESX host to another. If you are simply going from one LUN to another on the same ESX host you can and should use vmkfstools. You also need to use vmkfstools after you copy a vmdk with SCP to make sure file is properly written to the VMFS volume or you can experience performance degradation.

[oreeh]

In theory you can use this approach, but you shouldn't use *NIX tools to copy files to a VMFS volume.

The reason is possible fragmentation and therefore possible performance problems.

(Unix tools (like cp, scp, ftp, ...) create the file "on the fly" appending data,

vmkfstools first allocates the needed space and then copies the data)

[sean1017]

oreeh you're the man! that's twice you've been very quick and thorough in your response.

if you're ever in the chicago loop area, i believe i owe you a beer

now...about this vmkfstools, i read this http://www.vmware.com/support/esx21/doc/esx21admin_vmvkfstools.html and i don't see anything about how to copy from one LUN to another. do i have to do the export/import?

Message was edited by:

sean1017

[esiebert7625]

I've been there many a time (used to live in the burbs), I'd be willing to drink the beer for Oliver since he's way out in Germany...

The Server Config guide has an appendix on using vmkfstools...

http://www.vmware.com/pdf/vi3_301_201_server_config.pdf

Also method 3 of this tip has a example on using it...

http://vmware-land.com/Vmware_Tips.html#VM1

[oreeh]

Yes you have to do the export / import thing.

If the ESX sees both LUNs you only have to do it once!

If not you have to export then import - in this case use the 2gbsparse option, since this will save some time and space.

With ESX 3 the syntax has changed.

There's no more difference between export and import.

So the command to export/import for ESX 3 is:

vmkfstools -i srcvmdk destvmdk

[sean1017]

haha..well judging by the knowledge here and my lack thereof, i have a feeling that i'll owe plenty of you drinks by the time i'm caught up to speed.

i'll check out that appendix. thanks for the replies.

and just so you guys know...i am reading as much as possible, not just depending on this board...unfortunately though i can't manage to get through them quick enough to get what i need done finished before deadlines.

[oreeh]

haha..well judging by the knowledge here and my lack thereof, i have a feeling that i'll owe plenty of you drinks by the time i'm caught up to speed

We all were beginners...

[sean1017]

ok, i'm about to move some VMs from one LUN to another on the same ESX machine. The ESX server can see both LUNs.

I understand that i should use the vmkfstools -i srcvmdk destvmdk command but how do i specify the source and destination locations? Is there somewhere where i can list the current locations of the VMs?

[oreeh]

When you select a VM in the VM tree you see the currently used storage in the resources area in the summary tab.

If you for example have a LUN called storage1 and a LUN called storage2 you would issue the following command to copy test.vmdk from storage1 to storage2

vmkfstools -i /vmfs/volumes/storage1/test.vmdk /vmfs/volumes/storage2/test.vmdk

If the vmdk resides in a folder simply create the destination folder first.

[sean1017]

LOL... are you spying on me? That's actually the exact command i'll be using since i'm moving a test.vmdk from a lun named storage1 to storage2!

Thanks again!

[oreeh]

LOL... are you spying on me?

No, but storage1 to storageN are fairly common and test VMs usually have a disk called test.vmdk :smileygrin:

[oreeh]

Make sure to not accidentally overwrite a VMDK on the other storage.

If in doubt (~ only 99.99% sure) check the second storage first!