VMware ESXi with the free license (also known as vSphere Hypervisor) is a great way to get started with server virtualization and run your own hypervisor at home or in small environments. As soon as you have some sort of "production" workload running in VMs you will start thinking about how to protect them from data loss. You need backup ... but unfortunately with the free ESXi license VMware has disabled some functionality that is important for efficient backups of VMs: VADP (vStorage APIs for Data Protection) and CBT (Changed Block Tracking) are the features that all modern software products for VM backups make use of.
Nevertheless there are several solutions available to back up VMs running on free ESXi. And best of all these are available for free themselves. Here are your options.
The first option that I must mention here is William Lam's awesome GhettoVCB script. It is a script that runs inside an ESXi shell and is able to utilize VMware snapshots to back up even running VMs by cloning them to a secondary location (e.g. a remote NFS datastore). GhettoVCB is available on Github, it's well documented and has great community support.
I could stop now and ignore the voices of all the admins out there that want simple-to-use GUI tools to do their tasks - one graphical interface to create and manage backup jobs, maintain VM and backup inventories etc. GhettoVCB does not offer that, so let's look at alternatives that run on the most wanted and most hated operating system: Windows.
In the past Veeam's free edition of their flagship product Backup & Replication (resp. its former standalone version VeeamZip) was the de-facto standard for backing up VMs on free ESXi. But its current version does no longer work with free ESXi, because Veeam now focuses on the modern features (VADP and CBT) mentioned above that are not available with the free license.
So I will look at and compare two other products: Thinware vBackup and Trilead VM Explorer. Both are available in a free version and in one or two paid versions. For this comparison I will focus on the free versions.
Thinware's vBackup has been in beta for more than four years(!) now, but recently its version number jumped up from 0.3.2 to 4.0 and the end of the beta phase was announced for May 31st 2014. It requires a license key: Right now a beta license key (that unlocks all editions) is available for free, but that expires on May 31st. You can also already request a free license key for the Standard version or purchase licenses for the paid Advanced and Professional versions. The product page explains what features are available in what editions.
The software is easy to install, but has a prerequisite that you must install manually before: The VMware VDDK (Virtual Disk Development Kit). The vBackup Administrator's Guide is very clear about this and also provides a download link to the recommended version 5.1 of the VDDK.
VBackup's GUI is clear and well structured. You add your hosts and VMs to the Inventory view, create backup jobs for VMs and can manage existing backups in the Backups view. There is also a Scheduled Tasks view available, but it is without any function right now. When selecting it you are refered to the Admin Guide that explains how use the command line features of vBackup and the Windows Task Scheduler to create scheduled backup jobs. A manual process, but it works well.
For creating full image backups of VMs running on free ESXi you need to enable ssh access on the host, because vBackup basically just copies the VM files through ssh to a local disk. Incremental VM backups are not possible, but this is a limitation of ESXi rather than of vBackup, because the free license restricts the usage of CBT. A very welcome add-on is the GUI integrated ability to mount virtual disks from backups into Windows Explorer so that you can restore individual files and directories from Windows VMs' backups. This feature utilizes the vmware-mount.exe utility from the VMware VDDK.
Overall the software worked as expected for me, and I was able to create and restore full backups of VMs in a straight forward way. Tests were done with nested ESXi 5.5 hosts running the latest patch level.
Trilead VM Explorer
The current version 5.0 of Trilead's VM Explorer is available in a free and a paid Pro license. A detailed comparison of the two editions is available on their web site.
Installing the software is as easy as it can be. This time no manual steps are required, because the software is already shipped with the relevant portions of the VDDK.
Similar to the Thinware product the GUI is well structured and intuitive. In the Datacenter tab you add your hosts and VMs. By looking at the various options you will soon notice what the product name "VM Explorer" already implies: It is not only about backups, but you can use it to perform basic management tasks that you would normally use the vSphere Client for. You can power on and off VMs, manage snapshots, start an SSH or RDP session to the Guest OSs and look at a console screenshot. But what I liked best about the GUI is the fact that you can also access it remotely via a web browser.
According to backing up free ESXi the functionality is similar to Thinware's vBackup: You can create full image backups of VMs but no incremental backups. Enabling ssh on the host is not required but recommended by Trilead, because this improves transfer performance, especially if you enable the optional compression. An option that confused me is the possibility to create scheduled backup jobs for VMs, but then it turns out that you cannot really use these, because you are not able to enable the builtin Scheduler in the free edition. Even worse: You can either not use the Windows Task Scheduler to schedule backup jobs, because you cannot start a backup job through command line options (like with Thinware). File Level Restore (FLR) is also not available in the free edition, but this time there is a workaround: If you download and install the full VMware VDDK then you can use its vmware-mount.exe utility to manually mount a VM's virtual disk files from its backup directory.
What bugged me most about Trilead is the fact that I was not able to use it with an ESXi host that was running the latest 5.5 build (U1 + Heartbleed patch). It looks like VM Explorer checks the exact build number of ESXi and refuses to handle anything that it doesn't know. So I had to downgrade my test hosts to 5.5 U1 before doing my tests:
We can expect that Trilead will eventually fix that by publishing a new version of their product that is aware of the latest ESXi builds, but I wonder why they create this (IMHO unnecessary) dependency in the first place.
Trilead VM Explorer is the sexier product of both, but when it comes to backing up free ESXi hosts with the free product version then Thinware's vBackup offers slightly better functionality.
Here is a feature comparison table of the two products for a quick overview. Please note that it compares the free versions of the two products in combination with free ESXi. For additional features in paid versions and/or in combination with paid ESXi licenses please see the vendors' product pages.
|Trilead VM Explorer|
|VM Full Image Backup||x||x|
|Back up running machines|
|Requires ssh enabled||x||- 1)|
|Exclude disks from backup||-||x|
|Scheduled backups||x 2)||-|
|File Level Restore (FLR)|
(for Windows VMs)
1) Enabling ssh is recommended though, because it provides better performance
2) through Windows Task Scheduler
3) manually possible by using vmware-mount.exe from the VMware VDDK
What about Unitrends?
Back at VMworld 2013 in San Francisco Unitrends caused kind of a sensation and made a free version of their Enterprise Backup product available that enables you to back up up to 8 VMs that run on free ESXi! It looks like Unitrends is no longer actively advertising this, but the offer is still available. You should know though that it utilizes a different approach: You are not able to create image based backups at the hypervisor level with it, but "only" traditional file level and agent based backups from inside the Guest OS!
Of course this is also a valid approach. On the one hand restoring a VM in case of disaster is much more time consuming if you do not have an image based backup available, but on the other hand the agent based method enables you to create incremental backups which you can not create with the image based method and free ESXi.
Backing up VMs with large disks (e.g. file or database servers) is much more effective if you can leverage incremental backups, so why not combine both methods and use the best of both solutions: Back up only the VM's (small) system disk using an image based product and the larger data disks using an agent based incremental backup. This requires the image backup solution to exclude the data disks from backup processing - something that the free version of Trilead VM Explorer lets you do, but not the free version of Thinware vBackup ...
Best things in life are for free ...
... but I doubt that this applies to VM backup! In this post I have outlined some of the shortcomings that free ESXi and the free backup solutions have.
So if you run serious business on ESXi I would definitely urge you to invest some money in both VMware licenses (e.g. a vSphere Essentials kit) and licenses for a decent VM backup solution! It is not as expensive as you might think, and it will not only give you more and better features, but also vendor support. Think about it!
This post first appeared on the VMware Front Experience Blog and was written by Andreas Peetz. Follow him on Twitter to keep up to date with what he posts.