VADP backup and restore through SAN

[Alex_Zn]

1. Am i right that in case of SAN based backup, vmdk disks (snapshots) do not mount to VMware backup server, instead NetBackup operates on a block level of vmdk files (vmfs)?

2. In case of hot-add backup, VMware backup server can’t see vmfs file system, so it needs to mount vmdk files (snapshots) directly to VMware backup server to access data?

3. Virtula machine consists of view files, does snapshot applicable for this kind of files? How this files transfer in case of hot-add backup?

[Mark_Solutions · Accepted solution]

I think you will find a lot of your answers here:

https://www-secure.symantec.com/connect/blogs/nuts-and-bolts-netbackup-vmware-transport-methods-and-...

So ...

1. It does not mount it as such - it has visibility of it and is able to read it over the SAN

2. Host has direct visibility of the datastore so does not mount it as such

3. Not exactly sure what "view files" are - do you mean RAW partitions? If so then they cannot be backed up using vSphere - they must be actual vmdk's in the datastore

[Alex_Zn]

Hi Mark, Thanks for your answer.

I NBU VMware Admin Guide i see the next "

During a hotadd backup, VMware creates a linked clone of the virtual machine's disks

and attaches the cloned disks to the backup host. (The attached disks can be seen in

the vSphere Client interface.)

"

Does it mean that in case my second question, correct answer is is it mount, but not  a snapshot, it mount cloned disks?

[Mark_Solutions]

Yes - you are right - they are linked clones which are then attached to the VMWare Backup Host

Lots of limitations as i am sure you are aware but that is the principle of it

[Yasuhisa_Ishika]

Brief of hotadd transport is described here.
http://pubs.vmware.com/vsphere-50/topic/com.vmware.vddk.pg.doc_50/vddkDataStruct.5.5.html

When backup starts, it takes snapshot of virtual machine, linked-clone virtual machine is created from snapshot.
Next, vmdk of linked-clone machine is exposed to VMware Backup Host virtuan machine. It is just exposed, VMware Backup Host does not mount it as with other transport methods.