Freeing Up Space on Virtual Machines

A Virtual Machine (also referred to as VM) is actually an OS (Operating System). It can also be seen as an application environment which has been installed on software that emulates dedicated hardware. For end users, the experience of being on a virtual machine remains exactly as it would on dedicated hardware.

Hypervisor (specialized software) imitates the Server’s CPU or PC client, network, hardware, hard disk, memory and similar hardware resources entirely, which allows VMs to share resources. Multiple virtual hardware platforms can be imitated by hypervisor that are cut off from each other. This allows VMs to run Window Servers and Linux OS on the same underlying physical host.

Virtualization helps you deduce the need for physical hardware systems, which in essence help you reduce cost. Virtual machines lower the required quantity of hardware by efficiently using the existing hardware and all of this, reduces maintenance costs, cooling demands and power needs.

All in all they sound perfect. So what is the problem?

Most virtual machines dynamically allocate space so that not all of the disk space is occupied. This is actually good because the operating system and software take very little space. The problem however arises when you discover that the space once allocated, will always remain allocated. As you add and delete files, caches build up and after that even if internally your virtual machine occupies very little space, on your hard drive it might completely take over.

· How to Free Up Space Then?

If you are using VMware then you can use the compact tool that comes with it to recover space, but be warned that it only works ootb (out of the box) with Windows virtual machines. However, if you have a Linux virtual machine with a journaling file system similar to ext4 then you might need to make some extra preparations. In a nutshell, it means that the preparation would require for you create a massive empty file that only contains 0.

To start the process, you first need to stop running all the services. The newly created file will consume the virtual disk’s free space. When they will no longer be able to write to the disk, the running services will malfunction. You need to stop the running services before you create the file if you don’t want your database server to crash.

The command to create the file is: dd if=/dev/zero of=/dummy bs=4096. This command allows dd to create a file named dummy in /. The free space of the virtual disk will be the entire file size. For example if your configured virtual disk is 500GB and out of that 400GB is free, then the size of the file would be 400GB. You don’t need to have 400GB free on your physical disk where the virtual machine is stored on the real space needed will be 0 MB as you write zeros. After dd fills your system, it will exit out. You can delete the dummy file using rm /dummy.

You need to shut down your virtual machine and open the VM Player. On the panel, locate properties select the hard disk you want to compact and start the Compact tool from the Utilities drop down menu.

Doing that will start the compact tool and after a while you will see a success message informing you that the disk was compacted.

If you use cloud VMs then you should start using CloudBacko. The software helps you with smooth Hyper-V backup and VMware backup. This will more or less solve the spacing issue. To know more about CloudBacko’s features or to get it now, visit

Common Issues with Hyper-V Backup

More often than not, Hyper-V backups make you face a whole new troubleshooting learning curve which guarantees consistent and reliable recovery points for virtual machines. But the good thing about them is that at least they help you solve the problems early on when Hyper-V backup issues arise.

Mostly, the reasons for the entire backup process failing are failures within the virtual machines. Continue reading for some of the most common issues of virtual machine backup and how to get past them.

· Freeing Up Disk Space

Each virtual machine has a minimum of 300GB of free space on VHD (virtual hard disk) and is backed up through host level backups. If the VSC (Volume Shadow Copy) process is to take place within the virtual machine and succeed, then this space is necessary. The host Hyper-V VSS (Microsoft Visual SourceSafe) writer has to request this call from inside the virtual machine. After the VSS process has been completed by the virtual machine, and to ensure that the consistent state of the virtual machine, the backup process is continued by the host by accessing the stateful data (sometime referred to as quiesced data). The entire process is bound to fail if the space is simply not available.

The simplest solution to this problem is to free up space on the virtual hard disk that is low on space by either expanding the virtual hard disk or by deleting some files.

· Integration Components

Installed within supported virtual machines, integration components are set agents that offer maxed out performance and straight interaction with the host server hypervisor. Their main purpose is to assist the operating system with shut down, disk input & output, network input & output performance enhancements, timekeeping, guest host data exchange and VSS assisted backups. Installation of the right integration components on all supported virtual machines is very important. Inconsistent backup operations pop up when the down level or mismatched components are installed.

To get past this issue, you need to use only the latest integration components. You also need to understand that the updates or the upgrades to your backup software might need integration components too on all VMs that are that are on a specific backed up host.

· No VSS Writers Available in the Virtual Machine

Sometimes it might happen that no matter what you do, the backups for a singular virtual machine will continue to fail. If you have already ascertained that it is not due to low disk space or running the wrong integration components, then you have to understand that the VSS writers on the virtual machine might be in corrupt or inconsistent state. To know for sure, you can run the command line “Vssadmin list writers” and if the command returns with absolutely no data then you definitely have this issue.

On the affected virtual machine, you need to restart the service “Hyper-V Volume Shadow Copy Requester” to solve this problem. After that, you can try running the command again. If the process is successful then should be able to see all the VSS writers. To know for sure, you can check the status of all the writers in the output where they will be labeled ‘OK’.

The overall point of Hyper-V backups and backing up all virtual machines is to protect your environment from disaster. To ensure that the process succeeds every time, you can use CloudBacko. The software helps you backup virtual machines with ease to unlimited cloud backup services. To get the software right now, or to know more about its features, you can visit

VMware vs. Hyper-V: Which one is better?

For a very long time, the best choice for enterprise class server virtualization was VMware ESX (now known as VMware ESXi). But all that changed when some very serious changes were made to Hyper-V in Windows Server 2012 by Microsoft. Suddenly, there was something else that could be considered which was just as good. But most people still want to know what the main differences between the two are and which one is the better hypervisor.

This can be a little tricky as both VMware Inc. and Microsoft are reputable companies offering great products for the enterprise environment. At a first glance, you will find that both VMware and Hyper-V offer highly capable solutions. Both of them have a very similar feature set. Both offer similar core feature set like virtual machine (VM) migration, network interface card teaming, network virtualization and even virtual machine (VM) migration.

But that doesn’t mean that there aren’t any differences between the two. You just have to look closely to point them out.

· Dynamic Memory

Both VMware and Hyper-V adjust dynamical physical memory usage, putting the needs the guest OS (Operating System) first. However, VMware presents Dynamic Memory support to all guest OS. While on the other hand Hyper-V has historically supported Dynamic Memory only for virtual machines that ran Windows only. This feature has been changed since then.

· Scalability

When you consider scalability, you will find that the Hyper-V hosts can offer support as much as 320 logical processors, as opposed160 offered by VMware. Likewise, Hyper-V servers can handle up to 4TB of RAM, but VMware vSphere 5.1 Enterprise Plus is capable of addressing only 2TB of RAM.

· Licensing

Now we come to bigger differences and the most major of them is the way in which the products are licensed. Microsoft includes Hyper-V with Windows Server 2012. Singular Datacenter Edition license is valid for up to two CPU cores. It also permits an unlimited number of virtual machines running on the host. Without requiring an extra OS license the bonus feature of the Datacenter Edition license permits every virtual machine running on the host to run Windows Server 2012.

All core capabilities of Hyper-V are included in a Windows Server license. Extra features like ‘Live Migration’ don’t have to be paid for separately. While on the other hand, you have to pay premium prices for some of VMware’s core features.

· Services

As mentioned before, Hyper-V is included with Windows Server 2012. But it is likely that large organizations that necessitate enterprise management capabilities will also require System Center 2012 Virtual Machine Manager. But that is about it as far as the extent of Microsoft’s Hyper-V offerings go.

While on the other hand, VMware offers dozens of different products (or variations of products). But it has to be noted that while the offer of multiple feature capability might seem promising, most inexperienced administrators find it difficult to know which products to purchase.

SO which one of them is better? Honestly? It’s really hard to tell. Because of the similarity of the key features, both Hyper-V and VMware would suit just about any environment. But the end decision should be yours and what you feel comfortable deploying.

If your main issue is security while you backup Hyper-V and VMware, then you need not worry about that. CloudBacko, the best cloud backup software, offers smooth VMware backup and hyper-v backup and keeps your data 100% secure. You can get more in depth information about this amazing software at

Best Strategies to Apply When Backing Up Hyper-V

When compared to VMware’s virtual server product, market share taken by Microsoft’s Hyper-V is pretty low. Despite that, both have been known to share many similarities. These similarities become even more pronounced when it comes to backup. However, what you have to understand about Hyper-V is that one has to get some of its oddities just right if you want your backups to be consistent and successful.

Keep on reading to find out what are the best strategies and practices you can apply to make you backup successful each and every time.

Basics of Hyper-V Backup Strategy

The basics of virtual server backup dictate that should you back up multiple virtual servers in one physical box, then the chances of your I/O demands will increase significantly. Many users choose to backup Hyper-V at host level instead backing them up at individual virtual servers. The best practice in a physical environment would be to back up with only one agent per server. But this is would be over simplifying things. In this instance the most obvious place to back up would be the host which in fact combines the virtual machines. In this lies the difficulty of multiple virtual machines being handled by the hypervisor. The virtual machines are going to be active at the same time, therefore establishing the need for a way to stop the backup being carried out.

For this very purpose, a built in schema has been introduced by Microsoft called VSS (Volume Shadow Copy Services). VSS stops the virtual machine for a small duration and takes snapshot of its current state. This process is termed quiescence.

The three main components of VSS schema are a requester, a provider and a writer, which as the same suggests, request, write and implement the process in Windows OS and storage array in a larger environment.

When it comes to Hyper-V backup, VSS is an instrumental element. This means that the next time you look for an application for Hyper-V backup, make sure that is works well with VSS.

Main Things to Get Right for Successful Hyper-V Backup

VSS requires a minimum of 300GB of disk space to work. That is 300GB on individual VHD (Virtual Hard Disk). Most of this space is used to write data for quiescence, and from there it is copied by the backup application. The backup will surely fail with this disk space.

To handle quiescence, timekeeping, data exchange between host and guest, Hyper-V has numerous integration components. Without them being right all the time, the backup will either fail or remain inconsistent. To make sure that no such issues arise, make sure that you keep up to date with Microsoft patches.

And finally, a few things about the Hyper-V backup provider. As mentioned before, you need to check to the compatibility of VSS. Also you need to make sure that the backup provider has the capacity incremental forever backups.

The leading cloud backup software, CloudBacko has these abilities and so much more. CloudBacko is the best Hyper-V backup software and requires absolutely no training for you to get started. For more information, you can visit

Hyper-V Backup Issues and Solutions

blod-image-square-20141204The tiniest of errors inside your Hyper-V system can cause virtual machine backup failures. To keep your Hyper-V based virtual machines error free, look at the common issues and their solutions below. For more efficient backups, utilize CloudBacko; this premiere Hyper-V backup software will simplify all of the backup processes.

Not Enough Free Space

All host-level backups of virtual machines require 100s of GBs of free space for the Volume Shadow copy Service (VSS). This process is necessary for the VM to prepare the host for the backup of data; if there’s not enough free space available, the backup will fail.

You can resolve this issue by freeing up space on your virtual hard disks. Delete old and obsolete files. If this doesn’t do the trick, you will have to increase the hard disk space to provide the storage space required for the shadow copy process.

Corrupt VSS Writers

If you have taken care of the storage space issue and are still facing backup failure problems, check the consistency of the VSS writers. You can restart the ‘Hyper-V volume shadow copy requestor’ to address this issue. After the restart, run the “Vssadmin list writers” command; if all the VSS writers are listed and their status is ok, then the problem has been resolved.

Failed Hyper-V VSS Writer

VSS writer issues can also occur in host-level backups. The system center data protection manager will point you towards this particular problem, and when it crops up, it will affect all of the virtual machines created with the particular Hyper-V. You can restart the ‘Hyper-V Virtual Machine Management’ on the host to solve this issue.

Unnecessary Registry Growth

In some Hyper-V systems, virtual machine buses are left behind after a backup is completed which can fill up your registry. Compromised registry will cause instability in the volume shadow copy service and may even cause harm to the whole system. You will have to clean out these left behind, orphaned, devices to solve this issue; you can utilize several third party devices to perform the removal.

Protection of your backup is of the utmost importance, and ensuring secure and error-free backups is a big part of keeping your data safe. You should also use CloudBacko and its many features for reliable and secure server backups.

How to select a VMware/Hyper-V virtual machine backup tool

How to select VMware Hyper-V

Virtualization technology opens up new grounds for IT infrastructure administration and management, as well as new requirements for backing up the mission critical business data. Backing up for virtual machine is different from physical servers. Virtual machines can be moved from one host to another so you can move the host to guest OS mapping. Many virtual infrastructures are set up quickly and teared down.
IT system admins need to understand the specific requirements in their infrastructure, and learn the latest technologies on how it can optimally protect the virtual infrastructure. The following guide lists requirements of backup tools which applies for both VMware Hypervisor and Microsoft Hyper-V virtual environments.

1) Use a tool that supports both image-based and file-level backups

A full image backup is essential for backing up the virtual machines, as it encapsulate the entire virtual machine into a snapshot “image”. The backup software should cooperate with the virtualization software so that the backup software is backing up a stable snapshot rather than an actively used volume.
At the same time, the backup software should also support file-level backup. File-level backup is important as it helps to easily recover individual files, subdirectories or entire drives. It’s easy to implement and good for file server.

2) Use a tool that provides incremental block-level backups

Block-level backup feature can greatly reduce the amount of backup data transferred and stored. Only changed blocks of virtual machine disk files are backed up but those changed blocks can be combined with the original full to provide the most recent current image-level backup.
VMware provides the Changed Block Tracking (CBT) technology which can perform incremental backup. Virtual machines running on ESX/ESXi hosts can track disk sectors that have changed. If any blocks were changed since the last backup, Changed Block Tracking tags them and stores the information in a CTK file. CBT tells the Cloudbacko only to copy these changed blocks, avoiding copies of the entire VM.

CloudBacko utilizes this technology which can greatly reduce backup image size, hence using less cloud resources and network bandwidth. With this feature you can enjoy faster backup and restore.

3) Ensure offsite storage feature is available

Use a tool that provides offsite storage such as cloud storage. Check that the tool can connect to the cloud storage you are using or planning to use. As cloud storage services are plentiful, review the service cost model and reliability.
Cloud storage has the advantages of making content accessible anytime, anywhere, while shifting infrastructure maintenance tasks to cloud service provider. System can be easily set up to be fault redundant. Data and hardware redundancy offers an dramatic decrease the chance of your business-critical systems experiencing an outrage.
CloudBacko is designed for cloud backup from the start. CloudBacko can back up to multiple destinations, including Amazon S3, AWS compatible storages, Google Cloud Storage, Google Drive, Microsoft Azure, Microsoft OneDrive, Dropbox, OpenStack, Rackspace, FTP / SFTP sites, external USB drive, and local / mapped network drives.

4) Restore should be FAST

For those who have experience administering backup data, backup is only first part of the story.  Only after the backup can be restored successfully in a reasonable time frame, the backup job can be called complete. To ensure backup sets are in good shape, restore tests should be done frequently. Test if the restore can be completed in a reasonable time frame.

5) Use a tool that have compression

Compression is another way to make backup faster, hence saving backup time and storage space. Compression should be employed in the backup software to reduce the size of backup data repositories.

6) Backup applications

Safeguard data as well as applications. A virtualization backup tool should ensure applications inside VM are backed up. Not only application data or files are copied, but application states should have integrity that you will be able to restore them.
CloudBacko supports backing up Microsoft Exchange Server (EDB and mail level backups), Microsoft SQL Server, VMware vSphere ESXi (both Paid and Free versions), Microsoft Hyper-V, Lotus Domino, Lotus Notes, Oracle Database, MySQL, Windows System, Windows System State, as well as Files in desktops and laptops.

7) Keep cost under control

Consider your backup needs and match your requirements to the features of the backup tool. Vendors with enormous feature sets with a hefty price may be an overkill for small business users. Know your backup goals can easily keep your cost under control.
CloudBacko is trusted by many small business to perform backup and restore for their mission-critical business data. The one-time license fee includes lifetime free unlimited software upgrades.


CloudBacko offers the best-in-town price for advanced virtualization backup features. Download trial here.