In yesterday's post, I talked about esxRanger 3.0 and the integration of that product with VCB. Today, a colleague enabled VCB in a test environment we have running. The test environment consists of two ESX servers (DL580 G3) and just two 500GB luns from an HP EVA 5000.
To review the basics, VCB is a platform to facilitate taking backups of virtual machines. It provides a way to get to the virtual machine's disks using a fibre adapter in a Windows Server 2003 machine. Because of that, VCB needs to be installed on a physical machine running Windows Server 2003. VCB requires extra licensing and thus cost and is included in the Enterprise edition of VI3. You also need some scripts (integration scripts) that allow you to integrate VCB into your backup software. Our environment is using TSM (Tivoli Storage Manager) and scripts are provided to integrate with VCB. Basically, when you create a backup job, you run some pre and post-backup scripts to get the data onto the VCB server and to clean up afterwards. The big advantage of VCB is that it allows you to take a LAN-free backup of your virtual machines with no load on the ESX servers. Of course, it is only LAN free between the VCB and ESX server.
There are basically two types of VCB-based backups:
- Full vm: each virtual machine file including all disks (vmdk files) are dumped to the VCB server so that your backup software can back them up
- File mount: the virtual machine's volumes are mounted on the VCB server so that your backup software can get to the files in each volume
For a full vm backup, you need enough space on the VCB server to dump the complete contents of the virtual machine. For a file mount, you do not need any additional space.
So, in our test environment, a VCB server was setup with a single path to both our test luns. This is required as multipathing is not supported with VCB. VCB was installed, the TSM client was configured and the TSM integration scripts were installed as well.
You do not need to use your backup product and the integration scripts to test how VCB works because you can use the vcbmounter command line tool as well. This tool can be found (by default) in C:\Program Files\VMware\VMware Consolidated Backup Framework.
To create a snapshot of a full virtual machine, you can run vcbmounter with some command line options. For example:
vcbmounter -h <virtualcenterserver> -u <username> -p <password> -a ipaddr:<ip or name of vm> -r <a path you choose> -t fullvm -m san
This just creates a backup of a virtual machine with the ip address you specify behind ipaddr: to a path of your choice (-r). You need to specify the name of your VirtualCenter server and username and password because vcbmounter needs to send some instructions (such as create a snapshot) and also needs to get some information about which lun the vm uses.
Below you see a screenshot of vcbMounter's progress. I also specified another switch (-M 1) to export as a monolithic file instead of breaking up the vmdk in 2GB parts. The disk is compacted by default but not compressed.
I think it is clear from the above that you need enough disk space on the proxy to backup full virtual machines. The above backup took about 2 minutes. The vm had only 1 disk of 8GB and about 1,5GB of that disk was in use. Because this backup was compacted, you effectively only need 1,5GB of space on the proxy. If you would do this backup with vizioncore esxRanger 3.0, the file would be even smaller because they can also compress the data.
On the backup proxy, the saved files looked like this:
Instead of backing up the full vmdk, you can also mount the disk on the proxy so you can get to the files inside the virtual machine. Your backup software can then backup these files. To do a file mount, use the following command:
vcbmounter -h <virtualcenter> -u <username> -p <password> -a ipaddr:<ip or name of vm> -r <a path you choose> -t file -m san
The output of this command is:
The result in Windows looks like this:
This vm had only one volume (c:). In vcbMounter, I chose to mount the virtual machine's volumes under D:\Mount\XV401895-files. Under that folder, there were two subfolders: digits and letters. As you can see above, the letters subfolder contains a subfolder for each of the vm's volumes.
When you are done with the files in the mount point, don't forget to unmount the volumes. You do this with the following command:
vcbmounter -h <virtualcenter> -u <username> -p <password> -U <mount point>.
In the example above, my mount point is D:\Mount\XV401895. There is a file in this folder called umount.dat containing info needed to unmount the volumes.
In VirtualCenter, you will get some feedback from all the above operations in the recent tasks window:
It should be clear again that file mounts do not require any additional space on the proxy because nothing is copied to it. The virtual machine's disks are merely mounted on a Windows folder so they are there for the taking by your backup software.
Next steps for us are further testing with TSM and the integration scripts and also esxRanger 3.0.
