March 2007

When performing full VM backups with VMware Consolidated Backup (VCB), the end result of the backup operation is a copy of the VMs VMDK files, in 2GB blocks.  This format is similar to the format used by VMware Server and VMware Workstation, VMware’s hosted virtualization products.  Given that VMware Converter can convert VMs between ESX Server and the hosted virtualization products, I thought, “Why not use VMware Converter to restore VCB backups?”

So, with that question in mind, I set to see if it would work.  After conducting some tests, I have good news and bad news.  The bad news first:  it doesn’t work without some manual massaging of the VCB backup.  When you attempt to laod the VM’s files into VMware Converter, you receive an error message that VMware Converter “can’t determine the guest OS”.

Fortunately, the good news is that it isn’t hard to make it work.  Thanks to this VMTN forums thread, we can see that the process is actually pretty straightforward:

1. Edit the .vmx file to remove the “-NNNNNN” suffix that is automatically appended to the names of any VMDK files referenced in the .vmx file.  Make sure the VMDK filenames referenced in the .vmx file are indeed unique (they should be).
2. Rename the actual VMDK files by removing the “scsiN-N-N-” prefix from the filenames.  You’ll want to ensure that the filenames match the filenames referenced in the .vmx file.
3. Edit the VMDK index file (not the -sNNN files).  This is just a text file that references the rest of the files that comprise the virtual hard disk.  You’ll need to edit the filenames referenced in this file to ensure that they match the names of the actual “-sNNN” files on the disk.

That should be it.  After making those changes, VMware Converter should read the VM files without giving the “can’t determine guest OS” error, and then will let you select your final destination (which would typically be VirtualCenter).

Note that this will create a new VM, rather than restoring over the existing VM.  As a result, this may be most applicable when you need to recover individual files within a VM and aren’t performing file-level backups using VCB.  By using VMware Converter and creating a new VM, you can boot the VM up, get the files that are needed, then shut the restored VM down and blow it away.  This allows you to have the restore functionality of file-level backups but the speed of full VM backups.

VMware Consolidated Backup (VCB) is a new component of Virtual Infrastructure 3, and is designed to facilitate both full-VM and file-level backups of ESX-hosted virtual machines on a SAN. In its current release, it only supports Fibre Channel SANs, but support for iSCSI is supposedly coming in the next release. When used in conjunction with a third-party backup application (such as Backup Exec) and the appropriate integration software, VCB can provide the ability to backup VMs across the SAN (instead of across the network) without the need to install backup agents on every VM. The speed of backups is pretty good, too.

We performed a number of backups with VCB during our tests:

• File-level backup of Windows-based guest with the guest OS running
• File-level backup of Windows-based guest with the VM powered off
• Full VM backup of Windows-based guest with the guest OS running

All of the preliminary VCB tests listed above were performed using vcbMounter, a command-line tool installed on the VCB proxy server. The command we used looked something like this:

vcbmounter -h vcenter.example.com -u vcbservice
-p <password> -a ipaddr:10.1.1.100 -r E:\VMmount\VM1
-t file -m san

In the specific environment in which this testing was conducted, the hostname (of the VirtualCenter server, in this example) had to be changed from the default of 902, as the customer was using a non-default port number. This threw us for a minute, until we could determine exactly what port on which the server was listening.

This mounted the contents of this VM’s virtual hard disks on the path E:\VMmount\VM1\letters\C, E:\VMmount\VM1\letters\D, etc. We could then, of course, manually launch a backup of the files, but instead we continued with our preliminary testing and chose to wait on the Backup Exec testing until we were comfortable with vcbMounter.

This command worked, but in order to back up the virtual machine while it was shut down, we had to change the command slightly:

vcbmounter -h vcenter.example.com -u vcbservice
-p <password> -a name:VM1 -r E:\VMmount\VM1
-t file -m san

Here, the “name:VM1″ parameter was the name of the VM that we wanted to back up exactly as it appears in VirtualCenter, including case. (We did try this command using the same name with in different case, but it failed.) We could also have used the BIOS UUID for the VM, which can be retrieved using this command:

vcbvmname -h vcenter.example.com -u vcbservice
-p <password> -s name:VM1

Again, the name has to match exactly what is listed in VirtualCenter. One of the parameters returned by this command is the BIOS UUID, which you can then use in a vcbMounter command like this:

vcbmounter -h vcenter.example.com -u vcbservice
-p <password> -a uuid:<BIOS UUID> -r E:\VMmount\VM1
-t file -m san

By using the VM name or the VM BIOS UUID, we were able to make vcbMounter work both when the VM was running as well as when the VM was shutdown. Using the VM’s IP address or DNS name, on the other hand, only worked when the VM was up and running.

Once we felt comfortable with vcbMounter and vcbVmName, we begain testing of the Backup Exec Integration Module (BEIM), a set of freely downloadable scripts designed to provide some automation between VCB and Backup Exec. Although the syntax of Backup Exec’s integration scripts was a bit odd (and I think the documentation was incorrect in spots), the scripts worked well. Using the supplied scripts, we were able to perform both file-level and full-VM backups of selected virtual machines without any manual intervention required (the scripts handled all the mounting/dismounting/etc.). Watch out for spaces in the VCB path or in the VM names, though; they’ll cause the supplied scripts to fail. This article offers some extensions to the Backup Exec scripts that help address some of the shortcomings, including correcting the problem with spaces in the path or the VM name.

While VCB does have its shortcomings, it’s still a very useful tool to have in your backup arsenal. Between VCB full-VM and file-level backups and agent-assisted backups with an agent in the guest OS, there are plenty of ways to protect your virtualized servers.

I had been stubbornly clinging to WordPress 1.5.2, which worked just fine and, in all reality, provided all the functionality I really needed.  I figured it would probably be best to keep up with the newer versions of the software, however, so I decided to upgrade.

To give all credit to the WordPress developers, the upgrade process for WordPress itself was very straightforward and rather quick.  The trouble came in having to update or replace certain plugins that weren’t compatible with the newer versions of WordPress.  Combine that with some manual hacks I’d performed to help ecto work better with the Ultimate Tag Warrior (UTW) plugin, and you have yourself a real pain in the neck.

Fortunately, I stumbled across a really helpful nugget to assist in the ecto-UTW issue.  The XML-RPC Plugin for WordPress 2.1 incorporates the Robin Lu hacks (linked above), so that ecto can store tags in the keywords field and work properly with UTW.  Yay—no more manually editing code!

The rest of the problems surrounded updating the theme templates with new PHP calls to reflect new plugins; for example, you’ll note the “Recent Comments” section in the sidebar is different (required a new plugin).

Only a few things remain undone:

• The site search tags don’t seem to work just yet.  You get a “404 - Page Not Found” error when clicking on a site link tag.
• The site’s theme has not been completely updated in all places, so you’ll see different layouts in different sections of the site.  I searched for a new prebuilt theme I could apply to the site, but couldn’t really find any that I liked.  I guess I’ll just continue to tweak the existing theme.
• There are a few new plugins that I would like to use now that I’ve upgraded, but those haven’t been added to the site or incorporated into the theme just yet.

I anticipate that things should be worked out reasonably quickly, but I appreciate everyone’s patience in the meantime.

With everyone and their brother reporting the release of Fusion Beta 2, I’m hardly on the “cutting edge” with this posting.  To be honest, I don’t have the time to be on the leading edge of news postings, so rather than just regurgitate the same old stuff again here, I thought I might speak briefly as to the features that matter most to me as an enterprise IT consultant.

Here are the features that matter most to me:

• Virtual battery support:  This is a handy one because it helps my MacBook Pro’s battery last longer.  Previously, the Windows guests were not aware of the power status of the host, so they just ran full throttle and drained the battery in no time flat.  Now, the Windows guests can be aware of the power status of the host and adjust their settings accordingly.  Very handy.
• Improved networking support:  The added support for AirPort networking is a definite plus; I can’t tell you how many times I got bit by that one while sitting in a conference room.  Now I can use my Windows, Linux, or Solaris VMs across the WLAN while I’m in the conference room.  Again, very handy.  Although I still haven’t found any sort of advanced UI that lets us replicate the same kind of functionality as found in VMware Workstation (to create virtual switches and bridges), I’m hoping that will come soon.
• Snapshots:  I’m really glad to see this.  I don’t use VM snapshots very often, but this is one feature that really differentiates Fusion from the Parallels offering.  It also reassures me that Fusion isn’t going to be just a “consumer level” offering but that it will retain at least some of the professional-class features for which VMware Workstation is so well known.

Honestly, I don’t really care about the accelerated 3-D support; I very rarely play games on my Mac.  If I were a serious gamer and a serious Mac-lover at the same time, I’d probably have a separate gaming system for that.  Still, I imagine there are some graphics professionals out there for whom the graphics acceleration will be extremely useful.

So what do I still want to see in Fusion?  Expanded snapshot functionality approaching that of VMware Workstation and enhanced networking support (to help facilitate guest-to-guest communications with separately defined networks, plus NAT, host-only, and bridged networking).  Performance is pretty good now, and I’m sure it will only get better as the code is further reviewed and optimized during the beta/release candidate stages.

What’s still missing, though, is that one killer feature that would really set Fusion apart from any other Mac virtualization solution.  The problem is, I don’t know what that killer feature is.  Is it the equivalence of Parallel’s Coherence feature?  Is it the enhanced snapshot/linked clones functionality of VMware Workstation brought over to the Mac?  Or is it something else entirely?  If you’re so inclined, tell me what you think Fusion’s missing “killer feature” should be in the comments.

In the meantime, jump over to VMware’s site and get the latest build of Fusion.