Linked Clones for VMware Fusion with Somatic

Update: As of Fusion 6, this utility is no longer needed, as Fusion 6 includes proper cloning capabilities.

In the course of my day job, I need to be able to create VMs to try out my companies software as well as show customers how they might use our products to solve their problems.  To speed up the process of creating new and one-off VMs, I created a little utility called Somatic to help me do that much faster and by using much less disk space than copying a VM.

I use a Mac and, since the company that I work for produces a pretty good desktop virtualization solution for the Mac, I use VMware Fusion to host my VMs.  One challenge that I have is that those VMs take up a lot of space per VM, and that eats up the SSD in my MacBook fairly quickly.

VMware Workstation for Windows has a fairly nice feature that allows you to create VMs that are based on other VMs called Linked Clones.  Linked Clones allow you to create separate VM that points to the disks of another VM at a particular point in time.  This new VM then uses a set of very thin disk images that only contain the changes that it makes to the blocks of the source disks.  This means that the space used by the new VM is only just what is needed for that VM.

Somatic allows me to create a base VM image that has all the basic OS parts I typically don't change that often, and then create linked clones to that image that only take up a few hundred megabytes instead of the multiple gigabytes a full copy would take.  Also, linked clones setup much faster than a full copy, so I can quickly create a number of similar VMs to test out ideas with multiple machines.

The initial release of Somatic supports created full clones (copies) and linked clones of VMs.  The source VM for a linked clone must have at least one snapshot, and can only have one disk right now.  Future releases may address these limitations unless the Fusion team adds the linked cloning capability into the product.

If you want to see how I created this utility, you can also clone the Somatic Git repo and have a look at the source in the AppleScript editor.

Hopefully you find the utility useful!  If you have feedback, feel free to open issues at the github repo for Somatic.

Comments

Post a Comment

Popular posts from this blog

Ghetto Cloud Foundry Home Lab

Image
Over the past few months, I've been cobbling together my own Lab to be able to gain experience with Cloud Foundry.  Sure, I could have gone the much simpler route of bosh-lite , but I wanted to get a broader set of experience with the underlying IaaS layer in conjunction with working with Cloud Foundry. My lab hardware was purchased from various places (eBay, Fry's, etc) when I could get deals on it. Rocking the Ghetto Lab At a high level, the hardware looks like this: Machine CPU Memory Storage Notes HP Proliant ML350 G5 2x Intel Xeon CPU E5420 @ 2.50GHz 32 GB (Came with some disks, but mostly unused) vSphere Host 1, Added a 4 port Intel 82571EB Network Adapter HP Proliant ML350 G5 2x Intel Xeon CPU E5420 @ 2.50GHz 32 GB (Came with some disks, but mostly unused) vSphere Host 2, Added a 4 port Intel 82571EB Network Adapter Whitebox FreeNAS server Intel Celeron CPU G1610 @ 2.60GHz 16 GB 3x 240GB MLC SSDs, in a ZFS stripe set, plus spinning d
Read more

Using Snapshot Isolation with SQL Server and Hibernate

In the course of working on some deadlock issues, I found that MS SQL Server exhibits some unexpected (to me, at least) locking behaviors that can affect performance and cause deadlocks. In the end, I found that SQL Server provides an isolation level called Snapshot isolation which removes the need for locks on rows and removes lock contention. To use this isolation level, you need to execute the following SQL on the database that you want to use the isolation level with (replacing MyDatabase with your database name, of course): ALTER DATABASE MyDatabase SET ALLOW_SNAPSHOT_ISOLATION ON ALTER DATABASE MyDatabase SET READ_COMMITTED_SNAPSHOT ON Next, you need to modify your hibernate.cfg.xml file to add a property to tell Hibernate to use the Snapshot Isolation level: <!-- The 4096 isolation level is the setting to use with the jTDS or Microsoft JDBC drivers --> < property name =”hibernate.connection.isolation”>4096</property> Snapshot isolation is not a panacea
Read more

Fedora, Ant, and Optional Tasks

I've tried to be good. I've tried a number of times to use the version of ant that Fedora packages up into an RPM from the JPackage repos rather than caving to the temptation to install it myself manually. I also like to use optional tasks like ReplaceRegExp in my scripts to do all sorts of cool things. Of course, I see most of the installation instructions that refer to ant via RPM mention that I need to yum install ant-apache-regexp to get my optional task jars installed for this very nice task. Every time I've tried this, ant yells at me saying that it can't find the taskdef class for ReplaceRegExp. Huh? But I installed the proper, RPMs...didn't I? Usually at this point, I fall back to what works and just install ant by hand. However, I've finally realized why I've had so much trouble with this. There is one additional RPM that should be installed to get the classes that define all the optional tasks for ant called ant-nodeps. Before getting int
Read more