XenServer Backup Options – Part II

In this second of a two part series, we’ll discuss available options for XenServer Backup.

Citrix Xen ServerIn Part I of this blog post , I began discussing backup options for XenServer.  I touched on the tools that come with XenServer and cruelly ended it without getting into the topic of third party backups.  In this second part, I am going to completely skip over that subject and make you wait for Part IV.  Don’t ask what happened to Part III.  OK, I am done kidding around (for now).  Third party backup solutions generally fall into one of three categories: backups done through storage replication, backups performed at an OS level, and backups performed using snapshots through the XenAPI.

Storage Replication

Backups done through storage replication utilize the replication abilities built into your backend storage (SAN or NAS).  The VMs stored on your SAN or NAS get replicated to another site by the storage device.  This is both a backup and disaster recovery option.  However, it is probably the most expensive option because it requires two or more storage devices in different geographical locations with a pipe between them big enough to support the replication traffic.  File level restoration becomes a problem because the VM as a whole is replicated without a way to parse data inside the VM.

OS Level

Backups done utilizing at the OS level is the traditional method of backing up a server.  Even though these are virtual machines, they are still fully functional servers.  The hardware they run on is different, but in essence to the OS, that is a difference in drivers used.  The OS is still the same.  You can use your traditional backup software which usually (not always) places an agent in the OS to perform backups of the server system state, data, and files.  This could be solutions from Symantec, Carbonite, Acronis, ComVault, and hundreds of other backup vendors.  For those of you with smaller Windows server VMs and wanting to save money, you can even employ Windows Backup which comes with Windows.  OS level backups is a method in which you can keep from using multiple solutions providers and will provide the most granular level restore options for the OS, applications, and services.  One solution will probably handle it all.  However, you will be restoring a server the same way you would a physical server.  Fix the hardware, install the OS, install the backup agents as needed, and then restore.  This is a big differentiation from solutions geared towards backing up virtual machines as a whole image because they enable you to restore a VM back to its state at the time of backup without rebuilding the server.

Snapshots with XenAPI

Backups done through snapshots utilizing the XenAPI is a very common form of backup for a XenServer.  This method backs up the server as a whole image.  Many solutions utilize this method.  In fact, you can find free premade scripts people have posted that will perform this function for you.  You just won’t get any bells and whistles with a script.  And that is what differentiates the 3rd party backup solutions over just getting a script.  The bells and whistles 3rd party vendors include catalog and sort options, give broader control over the storage being used, and other features.  Some of these solutions have features that will mount the snapshot to allow you to perform granular recovery.  PHD Virtual (acquired by Unitrends last year) was one of the first well rounded support offerings for XenServer.  Over the last few years, it has grown to allow you to do granular level restores even for Exchange and SharePoint.  Quadric Alike is a well-rounded solution.  Its product trial is a free version for one XenServer that does not expire.  So, if you are a small shop with only one XenServer, here is a good free solution.
Ideally, a solution that provides both physical and virtual server backup solutions with granular level restore would be what a lot of administrators are looking for.  It would be your single backup product that covers both physical and virtual worlds.  SEP Software Corp offers such a solution as well as Symantec NetBackup.  Many of these solutions started out as a standalone products which were incorporated into a package or integrated into another solution.

As I stated, I am not covering anything in-depth and my purpose was not to review solutions in this article.  It is more about awareness.  If you would like to offer a suggestion I did not mention, please do so in the comments below.





Sr. Network Consultant


© 2014 Custom Systems Corporation

XenServer Backup Options – Part I

In this first of a two part series, we’ll discuss available options for XenServer Backup.

Citrix Xen ServerRecently, I have been asked about backing up XenServer Virtual Machines (VMs).  At first I was concerned that some of the people who asked have had a XenServer environment for a long time.  At this point, they already had backup solutions in place.  In essence, they were looking for something different.  More to the point, they were looking for a single backup solution that encompassed all their backup needs.  With that in mind, we can look at what is out there.  I am going to discuss the solutions I have familiarity with.  If I do not include a solution, it is not because I am excluding it or devaluing it.  If you know of a solution I do not mention, please post it in the discussions with a description of the product and tell me what you like about it.

Citrix (and others) categorize XenServer Virtual Machine backups into three types; Cold, Warm, and Hot backups.  These are also terms for disaster recovery and high availability, but they take on a slightly different meaning when referring to XenServer backups.  Cold and Warm backups refer to backups that cause service interruption.  A cold backup occurs when the VM is powered down completely.  A Warm backup will not power down the VM, but can still interrupt service while the VM is being backed up.  A Hot backup is one that will not interrupt service and keep the VM running.  The performance of the VM may be affected during a Hot backup, but the VM will still be able to respond to requests.

Let’s discuss backing up the XenServer host itself.  I have found very little need for a purchased solution to back up my XenServer Hosts.  The metadata on a host changes rarely and to install XenServer on a server literally takes only a few minutes.  Therefore, all I need to do is backup the metadata for the host from time to time.  I can accomplish this with command line tools.  Backing up a host server needs the ‘xe host-backup’ command.  To restore a host server, it takes a few steps.  First, install XenServer and run the ‘xe host-restore’ command using the file created from the backup command.  Then, you will need the XenServer install CD to run a ‘Restore from Backup’.  This can be scripted and works fine for individual hosts, but most times, we have a pool of multiple hosts.  You can still use the commands I discussed to make a host backup, but you need to use the ‘xe pool-dump-database’ command to back up the pool metadata.  You would then use the ‘xe pool-database-restore’ command to restore the pool metadata.  Again, scripting can help with these tasks.

Now, let’s talk about your basic XenServer VM backup options.  For immediate needs, you can export a VM, take a snapshot, or utilize existing server backup technology.  Exporting a VM and taking snapshots can be automated, but neither of them are true backup solutions providing resolution to backup strategies.  In fact, it is highly recommended to view snapshots as a temporary solution, not a full backup strategy.  Snapshots are categorized as a Hot Backup.  Snapshots will eat up your storage very quickly.  So will VM exports.  One cheap method of backup is to take a snapshot of a running VM, export the snapshot to an .XVA file, and then delete the snapshot.  Besides from storage utilization issues which get worse in big environments or growing environments, there a many other drawbacks to this method like automation problems, file level restoration complications, retention over time/restore point tracking, etc.

In part II of this post, I will discuss Hot backup solutions utilizing agents and options from multiple third party vendors.

As always, please post any questions or suggestions below. I look forward to hearing from you.

Sr. Network Consultant




© 2014 Custom Systems Corporation

Email as a trendsetter?

As we look at the current technologies that are developing, how do you know what the next trend will be?  You don’t have to look much farther than your email.  Email is not cutting edge, or flashy but it certainly has become the leading indicator of where IT is going.  Social media has supplanted Email for immediacy but Email continues to be at the core of any business because it is anecdotal and provides a timeline for ideas and decisions in many organizations.

Depending on your age and experience, you may look at this timeline from a different perspective. Back in the early days of IT, PCs and Macs only satisfied the personal needs of its user.  In order to provide some level of interaction with other PC and Mac users Email was designed as the primary method of communication.  Email to IT is like Morse Code is to the Telephone for the first 100 years of its existence.  The Telegraph using Morse code, and later a proprietary signaling method, did not become completely eliminated until February 2006, when the Telephone was ubiquitous.  My view is that Email will not be supplanted until Social Media is the primary method of communication for technology users of all ages.

When business became based on the personal computer, email developed into the “Gotta Have It” application.  It drove IT, and was required for business to effectively communicate across offices and time zones.  When the Internet developed into commercial usage in the 1990s, many of us used Email as the first application sending packets over the Internet to a remote server somewhere in the cloud.  When Windows became the defacto business desktop OS, we all clamored for a Windows Mail program, and Outlook survives to this day with Exchange Server.  When the cell phone developed into a PDA what was the first application that generated the most growth for Wireless Service Providers and devices such as Blackberry, iPhone, and Android…of course it was Email on your phone.

In today’s environment Email has become the most adopted cloud based application, whether you are using Gmail, Yahoo, or subscribe to a hosted business solution such as Office365 or Google Docs.  Email is the first thing we let go to the cloud.

So what comes next?  Let history show you…Think of the next most important app used after Email at each point of your timeline, is it ERP, CRM, Desktop Productivity, or the Desktop OS itself?  That answer will be the next service you will move to the cloud.

Paul R. Cook
Paul R. Cook
Vice President, Network Services Group



© Copyright 2014 Custom Systems Corporation

Cell Phone Myths Debunked

Know the truth about cell phone myths

These days, everyone has a smartphone. And I am sure at some point you have heard a cell phone myth or rumor about how to use or not to use your phone. Instructions like – Don’t user your phone while it is charging. Don’t leave it plugged in overnight. Or how about, always let the battery die completely before charging it. Well not all of these are true.

Technology has come a long way and batteries have become smarter. Typically, most new lithium ion batteries these days (which are used my major retailers such as Samsung and Apple) should last between three and five years if properly managed. Below are a few myths that I will explain.

Do I have to use a “real” charger?

One question that I have been asked quite frequently by people is if inexpensive (or what could be called fake) chargers will actually harm a cell phone. I read an article on the Life Hacker web site where they ran a detailed experiment where they put many different types of charges though the ringer. What they found was the “fake” chargers did not work at all or could even cause damage to the battery. I have even read reports where using a fake charger has caused the battery to melt, the phone to catch on fire, or even explode. When buying a phone charger, you really should purchase a name brand or off brand charger. Off brand being a charger that is still built by a reputable company, but not by the phone manufacturer.

Don’t use your phone while its charging.

One that I thought was quite funny the first time I heard it was “You shouldn’t use your phone while it is charging”. This is of course a myth and not something you should be afraid of. Using your phone while it is charging will not affect the phone or you in any way. Keep in mind, as I mentioned before, you do not want to use a fake charger. If you are, there is a chance that something could happen, but that is because of the charger and not the simple fact that the phone is charging while you are using it.

Why is my phone so slow?

I have also been asked many times why a smartphone slows down or seems to lag and what can be down about it. One common mistake about smartphones is that people see them as phones and not mini computers. They assume that they can be left on forever and that is just simply not true. Smartphones can could be considered mini computers and just like a computer need to be rebooted from time to time. You do not necessarily need to turn your phone off for any extended period of time, but turning the phone off and waiting 10 seconds then turning it back on weekly (or anytime it seems to really be lagging) is something I would recommend.

Most common question

Probably the most common question I have been asked regarding cell phone charging is “do I need to let the battery die completely before charging it”. The answer to this question use to be yes. Technology has changed and with the new lithium ion batteries, this is no longer the case. The short of it is, charge your battery anytime and as often as you would like. It will not hurt the battery. The long of it is that lithium ion batteries have what is referred to as cycles. This is basically the number of times the battery can be fully depleted and then fully charged. Batteries have a finite amount of these cycles and if you are constantly letting the battery die and then charging it, you are actually eating into these cycles. Batteries these days want to be charged and the devices that are using them want them to be charged. Do not worry about when or how often you are charging your batteries. One last note, I would not leave devices charging all day every day. Overnight is fine, but do not leave it plugged in all the time. That can be bad for that battery as well.

One last strange battery fact

Batteries will actually lose their charge faster when the device is cold (of the battery itself is cold). You do not want to leave a device in a hot car on an August summer day, nor do you want to leave it there on a cold February day. Keeping your device with you in the heat and A/C is how you will maintain the best battery usage and the longest life.

Can you think of any other strange rule about using your cell phone you’d like to share? Please add your myth or questions below.


Ryan Ash
Network Consultant
©Custom Systems Corporation 2014

Good Read: “The Goal: A Process of Ongoing Improvement”

Today, we’re taking a break and writing a book review:

“The Goal: A Process of Ongoing Improvement” by Eliyahu M. Goldratt and Jeff Cox

While I was growing up in a suburb of Philadelphia, my father was a controller at a manufacturing plant not far from our house.  Like many boys, I was interested in what my father did for a living.  I would watch my father walk out the door every morning in his suit, excited and ready for whatever challenges he met that day – and later in the evening greet a tired and slightly agitated man at the door – tie loosened and crooked, jacket wrinkled and slung over his shoulder.  Often in those days, Dad would come home for dinner but then have to go back to the plant.  Yet, he never missed my soccer games, my sister’s ice skating competitions, or my brother’s baseball games.

Many years later, when I first became a father, I asked my dad “How did you do it?  How did you find a way to balance work and family?”

“First,” he said, “go to church more.  Then read this…”

That’s when he handed me a book titled “The Goal: A Process of Ongoing Improvement” by Eliyahu M. Goldratt and Jeff Cox.

“The Goal” is almost a how-to manual disguised as an action-thriller.  Whether your are involved in project planning, manufacturing, or just love a good “think outside the box” story, this is a great read.

I find myself quoting this book all the time with family, friends and coworkers.  When faced with a challenge, remember to ask yourself this question: What is the goal, and how do we solve this in terms of the goal?

Even though it was written 30 years ago, Mr. Goldratt’s tips and advice regarding thought process, his theory of constraints and bottlenecks is just as relevant today.   I’m going to go home tonight to find this book and read it again.

How about you? What book have you read that has left a lasting impression on your life?



Chase Reitter
Network Consultant