We will quote a nicely written article from wikipedia.org, "A virtual appliance is a virtual machine image designed to run on a virtualization platform (e.g., VirtualBox, Xen, VMware Server).
Virtual appliances are a subset of the broader class of software appliances. Installation of a software appliance to a virtual machine creates a virtual appliance. Like software appliances, virtual appliances are aimed to eliminate the installation, configuration and maintenance costs associated with running complex stacks of software
A virtual appliance is not a virtual machine, but rather a software image containing a software stack designed to run inside a virtual machine. Like a physical machine, a virtual machine is merely a platform for running an operating system environment and by itself does not contain application software."
A Zettar ZCloud Virtual Appliance is a virtual appliance that contains the Zettar ZCloud software, which implements a most often used subset of the Amazon Web Services (AWS) Simple Storage Service (S3) REST APIs. Normally, it runs as a daemon to be accessed over a network (in host, LAN, or even the Internet via a proxy).
zcloud comes as a self-contained binary executable. It doesn't depend on any other common system daemons to run. It stores data in an object-based format, and thus is agnostic to the types of filesystems that are employed for its data storage. There are numerous filesystem choices available.
The most precise and detailed info on the Zettar ZCloud software is provided in the man page contained in the zcloud-doc deb package, which you can download and install on a computer (physical or virtual) running the Linux operating system.
As a start, you can use it as a local Amazon Amazon Web Services S3 sandbox. The Web Services interface is identical to that offered by AWS S3. Being a self-contained sandbox, you can deploy it locally, even on a tiny netbook. A rapid application of the software develop/test/stage/deploy cycle is again a reality. You can analyze your cloud applications quickly, since all logs are available locally and in real-time. There are other potential usages that we probably haven't thought about. If you come up an innovative use of ZCloud, please do let us know!
VMWare Fusion, and Microsoft VirtualPC 2007 SP1, Linux KVM, Xen, and VMWare Server. More will be added soon.
Since ZCloud is local, highly efficient, simple, low cost, and fast. You will enjoy much simplified and faster cloud application development. In fact, Zettar Inc. developed ZCloud because we needed it ourselves.
In addition, since it's multi-user and multi-client, so unless you have a very intense and busy development needs, most likely one instance of ZCloud should be sufficient for your organization, resulting signficant saving in time, management, and money.
Foremost, you no longer need to deal with "eventual consistency" issues that a highly distributed system such as AWS S3 always exhibits. Therefore, you can analyze and test your cloud applications right where you are, when you want to. No more waiting for AWS S3's log deliveries. Furthermore, all logs are provided in the standardized Common Log Format, for which you have plenty tools available for analysis. Better understanding, fewer bugs, shorter development cycles, and faster in generating revenues as a result.
In fact, you may not even need to have Internet connectivity at all. You can run a ZCloud virtual appliance on an in-host network, and access it from other virtual machines running on the same host. Portable AWS S3 is a reality with ZCloud.
Other than the above, you don't need to worry about un-expected credit card charges showing up on your monthly statements, due to some overlooked bugs. With ZCloud, you can always stage locally, make sure everything works well, before the actual deployment - the proven way and best practice for server application deployment.
You can store virtually any kind of data in any format, just like what you would do with the real Amazon AWS S3.
Individual ZCloud objects can range in size from 1 byte to practically any arbitrary size, just like what AWS S3 does in this regard. The number of objects you can store is practically limited only by the available data storage to the ZCloud Virtual Appliance.
Just like the real Amazon S3, ZCloud uses the same simple key-based object storage scheme. When you store data, you assign a unique object key that can later be used to retrieve the data. Keys can be any string, and can be constructed to mimic hierarchical attributes, again like the Amazon AWS S3.
ZCloud implements a most often used subset of the simple, standards-based AWS S3 REST web services interfaces that are designed to work with any Internet-development toolkit. You will enjoy the same simplicity and functionality that AWS S3 provides, and the majority of the software that have already been written for AWS S3 - a rich ecosystem.
As reliable as the host on which you deploy the ZCloud Virtual Appliance. Please note that this release is meant to be used as a sandbox for developers and software QA engineers. It's not designed for a high availability data storage like the actual Amazon AWS S3.
Each and every ZCloud Virtual Appliance always comes with a 14 days free trial license.
Other than the trial license, Zettar Inc. also offer a license that ties a ZCloud Virtual Appliance to the hardware address of the host on which it runs.
The license is one time and perpetual.
For now, the simplest and most direct way is to order a ZCloud Virtual Appliance from the Zettar Store.
Yes. If you have a Free Trial license, you can upgrade it to a Single Server License. We will introduce other, more feature-rich options that you may wish to upgrade to soon.
A basic paid license that you have acquired from Zettar Inc. entitles you 30 days free after sale email support and installation assistance. The license also enables your ZCloud Virtual Appliance to receive automatic updates up to a year. The license itself is perpetual. Additional support, professional service, and upgrades are available with additional fees.
Memory: 1024MB; Virtual CPU (aka VCPU): 1; Disk Space: 16GB
All of them are adjustable, depending on the available resources of the physical computer (aka host) on which the ZCloud Virtual Appliance runs. Please see other FAQs of this section for more info.
All virtual appliance images are provided in a compressed format, of a size around 150MB. Once expanded, each image takes about 450MB to begin with.
With all supported virtualization platforms, you can adjust the assigned memory to the ZCloud Virtual Appliance via either a command line tool, or a graphical UI.
Note that after the adjustment, you may need to restart the ZCloud Virtual Appliance. Please consult your particular virtualization platform's support documentation for further details.
With all supported virtualization platforms, depending on whether your physical computer's CPU(s) have hardware based virtualization support (i.e. Intel VT-x and/or AMD-V), you can adjust the number of virtual CPUs to the ZCloud Virtual Appliance via either a command line tool, or a graphical UI.
Note that after the adjustment, you may need to restart the ZCloud Virtual Appliance. Please consult your particular virtualization platform's support documentation for further details.
Actually, there are many ways to deal with this issue. You can actually expand the default 16GB ZCloud Virtual Appliance to any size that your physical computer may have space to accomodate. If you seach the Internet use Google using the search phrase "increase virtual machine disk size", you will find many hits
We at Zettar actually prefer a simpler solution: importing storage capacity from a NFS server, with your Virtual Appliance as a NFS client.
Then, you can just use the ZManager Web UI to assign the larger, imported space to the ZCloud software. This is quite straightforward to do, and involves very few steps. We will soon update the Virtual Appliance's menu with this option. It will soon come to our paying customers via Zettar's transparent and automated Debian repository software update mechanism. Stay tuned.
ZCloud employs the same cryptographic methods that Amazon S3 uses to authenticate users. It also always keep your data private. Note that we envision that its main use for you is a sandbox behind your organization's firewall. If you would like extra security, there is no restriction on encrypting your data before storing it in ZCloud. It supports HTTPS too.
Since ZCloud doesn't provide anonymous accesses to a bucket, we suggest this approach: ZCloud supports multi-clients. Thus, you can create several virtual machines on perhaps a few different physical hosts, all on your own LAN, and then run several S3 clients on each VM. All clients must use the same credential so they access the same bucket.
Owing to the intensity that you can introduce in such a setup, you can actually stress test your applications more this way.
Ideally, exposing your buckets directly may not be the best approach. You may wish to introduce a front end so that people can access all content anonymously instead. A Web server can be easily setup for this purpose. This is similar to what Amazon recommends: distributing your content stored in S3 using CloudFront, instead of using S3 directly.
Please keep in mind that ZCloud virtual appliance is meant to be a cloud application development tool - a local sandbox. It's not intended as a high availability, large capacity cloud storage service engine.
Nevertheless, should you wish to have your data more "protected", we recommend the employment of solid state disks (SSD), and/or use a clustered filesystem such as GlusterFS as zcloud's underlying filesystem. Such additional measures will definitely provide a much better data integrity protection than a regular filesystem on a conventional hard drive.
ZCloud depends its underlying data storage filesystem to ensure data integrity. Nevertheless, just like the real Amazon AWS S3, ZCloud calculates checksums on all network traffic to detect corruption of data packets when storing or retrieving data.
Thanks for asking! Although not yet with this initial release, we have laid the ground work, and are looking at introducing the capability soon.