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VMware Hot-Add Backup host also a SAN client?

Created: 10 Oct 2012 • Updated: 21 Dec 2012 | 7 comments
E-3S's picture
This issue has been solved. See solution.

Hi all,

My customer has NetBackup configuration v7.5.0.3 in a VMware 4.1 environment.

We cannot do VMware backups using the standard Backup-host solution. I would like to know if anyone has tested a "Hot-Add" backup solution in a SAN client?

In other words, is it possible to make the "Hot-Add" virtual machine also a SAN client so that the backups flow is going through the SAN?

Hope my request is clear. Thanks in advance.


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RLeon's picture
VirtualED said:

Using the SAN client feature to backup a VM with a client inside of it is not supported.  SAN Client only supports Qlogic HBA, and the HBA presented in a VM is not a QLogic even if the Host adapter is a QLogic.  A Virtual HBA is always presented in a different format.

A VM cannot be a SAN Client.
And since a Hot-Add host is a VM, and we know that a VM cannot be a SAN Client, it follows that a Hot-Add host cannot be a SAN Client.

Hope that helped.


E-3S's picture

Hi RLeon,

thanks for your reply.

Humm!. I do not really agree with what "VirtualED" wrote in his post.
Extract from the Symantec NetBackup™ SANClient and Fibre Transport Guide v7.5:
"The HBAs on the SAN clients can be any supported Fibre Channel HBA. The HBA ports must operate in the default initiator mode."
On the Media server, this is different. HBA has to be a Qlogic for the FC port turned to Target.
I already have an AIX virtual machine (Lpar) using a NPIV configured as a SAN client.
But I still wondering if a SAN client will work on a VM on VmWare. And on top of that, if this VM/SAN client could be used for "hot-add" backup for others VMs. 



RLeon's picture

The above technotes are for Backup Exec, and the situation described is not exactly related to yours. For one thing, Backup Exec does not have the SAN client feature.

I post them because I think what you are trying to do is what Symantec would call "Alternative Configurations"; as they are called in the technotes.
Something that is not explicitly documented to be supported, but not entirely impossible to do.
And indeed, people will report that such "Alternative Configurations" can be verified to work.

I couldn't find similar/related technotes for Netbackup. Perhaps someone else could help.


Bmitche's picture

When we first started to test VM backups....we tried SAN. Our storage guys had fits when we had to present all datastores to the media servers. I gathered some benchmarks.

We then tried NBD(network). The results were close enough to SAN that we thought it was much safer and our storage guys would quit crying. We have multi 10gb network so the speeds were pretty good. Yes we had to install the agent on all of the VM' biggie.

Up until a couple weeks ago...all of my media servers were physical. I built a virtual media server and added it to the mix. I happened to notice one of the backups was using a transfer mode of "hotadd"....and it was running quite a bit faster than the other backups. After researching appears that SAN and hotadd are kind of similar. Hotadd "mounts" \ "adds" the disks it needs within the virtual media server. If you look at disk management on the vitual media server during a hotadd will see the luns of the VM you are backing up. They are all offline. DO NOT try to on-line them....I believe it will wipe-out the data on these disks. In our enviroment we segregate our datastores by cluster. So if I want to backup the vm's in the test cluster...I must have a vm media server in the test cluster or "share" the datastore access between clusters.

Just as an example....if a single backup on NBD(network) ran at 70mbs....using hotadd it now runs at 110mbs. These numbers are approximate but atleast in my case there is a big improvement.

Since I am very new to hotadd please don't take anything I said as "the way to do it". It seems to work for our enviroment.

E-3S's picture

Hi Bmitche,

Thank you for this information. Just quick questions regarding your virtual media server:

- How do you send data from the media server? To disk, to tape. Did you define NPIV (Virtual FC Port) to write to tape?

- Are you sure the data is going via the SAN from this media server to its storage Unit?

Many thanks in advance for your reply.


Bmitche's picture

The data is going from the virual media server to a physical media server which has the MSDP(dedupe pool) and the tape library on it. It goes over our 10gb network. I have a dual 10gb network card in the physical media server and the connections are It is a 20gb connection. I assigned a VMXNET3 network adapter to the virtual media server so it also has 10gb network. The data path is... via SAN from my backend storage(HP eva's),(HP 3par),&(HP XP24k) to my virtual media server. Then via dual 10gb network to MSDP, then via internal bus to tape on the physical media server. My MSDP(dedupe pool) is 6gb-SAS connected to the physical media server. The library and drives are 8gb fiber connected to the same physical media server.

Over the next couple months I will be looking at hooking my library and tape drives to the fabric, after that I will try to "grab" some of the shared storage from our disk arrays for MSDP. If I am succsesfull....everything will be traveling over 8gb fiber.

My speeds right now are very good. I am making our backup windows with plenty of time to spare. But there is always room for improvement. Baby steps

Mark_Solutions's picture

Hot Add would generally pass the data via the LAN

When using de-dupe that advantage is that the VMWare Backup host can do clientside de-dupe so that it passes very little over the network to the media server.

The HotAdd client can only do this for any datastores it has visibility of, so you would generally need one per ESX Server but if it has visibility via the ESX host it is on of all Datastores then you only need one to backup everything you have (though adding more scales the power and throughput of your backups)

We did tests of this during my Appliance training and Fibre Transport was not used for this method - i am guessing that if it was possible then it would have been done - so as far as i am aware you wont be able to combine HotAdd and FT

Hope this helps

Authorised Symantec Consultant . Expert Partner.

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