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Where to use data deduplication technology

Posted on July 9, 2009 by brennels

Lauren Whitehouse wrote a good article describing the different options when it comes to data deduplication and was published on http://searchstorage.techtarget.com. this week. 

Read the full article here

“Data deduplication promises to reduce the transfer and storage of redundant data, which optimises network bandwidth and storage capacity. Storing data more efficiently on disk lets you retain data for longer periods or “recapture” data to protect more applications with disk-based backup, increasing the likelihood that data can be recovered rapidly. Transferring less data over the network also improves performance. Reducing the data transferred over a WAN connection may allow organisations to consolidate backup from remote locations or extend disaster recovery to data that wasn’t previously protected. The bottom line is that data dedupe can save organisations time and money by enabling more data recovery from disk and reducing the footprint and power and cooling requirements of secondary storage. It can also enhance data protection.”

What are your thoughts on where to use data duplication?

 

Filed under: Backup and Recovery | Tagged: , , | 1 Comment »

Double-Take 101: Cross-OS Replication/Protection

Posted on July 7, 2009 by miketalonnyc

When Double-Take Software released a series of products and strategies to perform migration from one hardware platform to another, many clients began to experiment with these new tools to help make their jobs faster and easier. Along with the ability to move between platforms (such as from physical to virtual), many clients wanted to know about options for moving between versions of Windows and between Windows and other OS’s. While Double-Take Availability, Double-Take Move and Livewire can assist with these procedures, there are some limitations to be aware of.

First and foremost, while Double-Take Software products support both Windows and Linux, you must stay within the same basic OS for any source/target connection. That means that you can go between any version of Red Hat Enterprise Linux (RHEL) and/or CentOS to any other; SUSE Enterprise to SUSE Enterprise only and Windows to Windows only. Going between types of operating systems is not currently supported by any of the Double-Take Software products, and as a matter of fact the consoles are designed to actively prohibit you from trying it. This is mainly because these different OS’s use wildly different formats for storing and processing data, and an I/O operation from Windows wouldn’t be committable on a Linux OS and vice versa.

Within the same base OS, there is a bit more flexibility. Generally, Double-Take Software products can move data between any two versions of the same basic OS. So, for example, you can replicate data from Windows 2003 to Windows 2008. Whenever possible, security and other attributes will be maintained, as long as the target OS can accept and process the security and attribute identifiers applied to the source. When moving from an earlier OS to a later one, this isn’t generally a problem. However, while moving data from later to earlier is allowed, not all attributes may be accepted by the Target and therefore may not replicate. This doesn’t break replication, but it does mean that the target data will get whatever inheritable permissions exist on the volume we’re replicating to. So when going between versions of an OS, it’s best to replicate from an older source OS to a new target OS whenever possible. Keep in mind that this only applies to the version of the OS, the version of the Double-Take Software product should be identical on both machines.

System State Protection (only available on Windows platforms) is another story. While data can safely move from Windows 2003 to 2008 – in example – the system state cannot. This is for one very obvious reason, they’re different versions of the Windows system, and therefore not compatible. So when using Double-Take Software tools to migrate between different versions of Windows, you will be able to move data only, not OS binaries, application binaries or registry settings. Usually, the installation and configuration of a Windows 2008 server and its applications is so different from that found on Server 2003 that you would rarely ever want to move system state, so this is not usually an issue.

Livewire is a different set of circumstances, however, as it is used to store system information and data for eventual restore to another server entirely. For this tool set, you may replicate everything including system state (the default for Livewire protection) to an image server that is running any valid version of Windows. Today, that includes both the Windows Server 2003 and Windows Server 2008 product lines, and will soon include Windows Server 2008 R2. The image server must be the same or newer than the source machines, but does not need to match the source machines or the recovery server that you will restore to.

This doesn’t mean that mixing and matching OS’s is without consideration, though. When you go to restore, if your recovery server is not the same OS as the image server, then you’ll need to install Livewire manually on that recovery server before you run the recovery wizard. The reason for this is that the image server can only push the version of Livewire it has installed, which wouldn’t match up with the OS on the recovery server. By manually installing Livewire on the recovery server, you ensure that the version is correct, and bypass any mismatch issues. Also, be aware that the recovery server will need the same version of Windows as the original source machine was running. This is because we will be restoring system state to that recovery server, and therefore will need the same OS installed.

Let’s use an example to illustrate this. If I have a Windows 2003 x86 server in production, I can replicate to a Windows 2008 Storage Server Edition x64 Image Server with no issues at all. When I go to restore, I can perform that restore to any Windows 2003 server, but I have to install Livewire on that recovery server before I begin the restore operation.

Finally, in the Windows world, there is the ability to have multiple levels of the same OS version. For example, you can install Windows Server 2003 in both Enterprise and Standard versions, as well as a Datacenter version for larger implementations. The same is true in Windows 2008. Double-Take Software products can safely move between product levels with no issues, however make sure that your target system can support the level of the OS installed on the source if you intend to protect the system state. The target will become the source in all respects after a failover, and this includes taking on the same level of Windows that the source had. Livewire will produce the same result after restoration to a recovery server, and therefore that hardware should be capable of running the same OS level that the source held before it failed.

OS mixing and matching is sometimes required due to limitations in server availability, licensing restrictions or a host of other factors. Double-Take Software products can allow you to move between different versions of the same OS, as long as you follow the basic rules outlined here. While we cannot make multi-version migrations as seamless as we’d like, we can definitely assist you and make them as easy as possible.

Filed under: Best Practices, Double-Take Availability, Double-Take Backup, Double-Take Move | Tagged: , , , , , | Leave a Comment »

Troubleshooting 101 – is it Double-Take or the Network?

Posted on June 30, 2009 by miketalonnyc

We do see customers who – for whatever reason – are seeing slow throughput on the Double-Take or Livewire connections between two servers and/or sites. It can be difficult to figure out if the problem lies with the replication engine or the network itself. There are several great network telemetry tools you can obtain to help you find out, but the most available one is also the one most users don’t think to try.

If Double-Take is running slowly across a link that you believe should support faster throughput, the best first step is to stop the Double-Take connection and test the link. The easiest way to do that? Simple, take a 100MB file and drag and drop it from a folder on the Source to a folder on the Target. See how fast it can go across the network between the two servers. Believe it or not, this simple test has helped more than a few of our clients find out they were not getting the network throughput they thought they were – and in some cases less than they were paying for.

Here’s a real-world example: A client was having trouble because Double-Take was only transmitting data at a maximum throughput of 3.6Mb/sec over a link between New York and London. The ISP that provided the link had rated it at 45Mb/sec, and since they were not even close to 50% saturation on the link, they were rightfully concerned with the slow throughput they were seeing. Double-Take was queuing a large amount of data, so we definitely had more than 3.6Mb/sec of data change, and none of us could figure out why they were seeing such slow connectivity.

Finally, one of our Tech Support Engineers noticed that other data was also moving slowly across that link, and decided to check things out. Not having a network management tool handy, he simply dropped a file from a NY server onto a folder on a London server. The resulting transfer only moved at 3.5Mb/sec – slower than Double-Take was moving data! As it turns out, the ISP was single-thread limiting connections over that link (which turns out to be a somewhat common practice on inter-continental links). This meant that anything transmitting with a single thread – like both Double-Take and standard NTFS file transfers – would be limited to at most 3.7Mb/sec no matter what.

In this particular case, a WAN optimizer fixed the problem, but the point is that while we were attempting to troubleshoot a Double-Take issue for several days, the problem was actually a network hiccup. If we’d tried the transfer to start with, it would have been apparent that the Double-Take transmission system was working properly.

Truth be told, we do occasionally find instances where Double-Take isn’t transmitting as fast as it could for one reason or another. We can get those fixed up quickly, but first we have to confirm that the limiting factor isn’t actually the infrastructure. Simple tests like checking file transfer times can go a long way to clearing up issues quickly. In Server 2000 and 2003 you will need to do a little math to figure out the transfer rate, but in Server 2008 you can see how fast the file is moving right in the UI. If it’s a lot slower than the line speed, then there may be an underlying networking issue that’s keeping us from moving at top speed.

Filed under: Best Practices, Double-Take Availability, Double-Take Backup, Double-Take Move, GeoCluster | Tagged: , , , | Leave a Comment »

Outsourcing disaster recovery services vs. in-house disaster recovery

Posted on June 29, 2009 by brennels

By Jacob Gsoedl
29 Jun 2009 | SearchDisasterRecovery.com

Jacob Gsoedl published a good article today on outsourcing DR vs. doing it in house.

“Whether to create a disaster recovery (DR) site in-house or to outsource disaster recovery is a fundamental decision that needs to be made when creating a disaster recovery strategy. The in-house approach may be tempting, with the assumption that the work related to DR can be performed by existing staff. Unfortunately, experience shows that in-house disaster recovery is more likely to fail than outsourced DR services.

According to an IDC study, enterprises that didn’t outsource lost on average $4 million per disaster incident across a variety of business functions (e.g., sales/marketing, financing, e-commerce). In contrast, enterprises that outsourced to a third party lost an average of $1.1 million per incident. The study adds that companies that leverage an in-house model spend 32% more than those opting to outsource.”

Read the rest of the article here

Filed under: Backup and Recovery, Disaster Recovery, Double-Take Availability | Tagged: , , , | Leave a Comment »

Shifting the Backup Paradigm

Posted on June 24, 2009 by brennels

Trying to determining what data is important, why choose? Select it All! Having a hard time trying to get your business departments to identify what is the most critical data to backup? This is may be the most common problem for IT managers, not only trying to extract that information but then setting up the backup solution to only capture the data required. The better solution is not having to determine what is critical and selecting it all. Why go through the time of conducting business impact analysis just to find out at the time of disaster that you didn’t capture the one file or system for recovery because no one identified it as being critical.

The primary reason IT managers would go through this pain staking process of only selecting the data needed was due to infrastructure limitations which aren’t as much of an issue today. Usually there was limited disk space, tape devices, offsite storage costs or WAN bandwidth limits on the amount of data that could be transferred in a 24 hour period. These limitations aren’t nearly the hurdle that they use to be. Storage is much cheaper and more flexible that it has ever been, bandwidth is cheaper and with solutions like SilverPeak and Riverbed there is the ability to expand and optimize the existing bandwidth in place versus upgrading throughput. Because these limitations have been removed data center managers now have the ability to select a full server workloads or entire LUN’s full of virtual disk images.

Not only does this prevent the potential of missing or forgetting to back something up it provides an easier method of recovery. Now you don’t have to worry about is that file in the right directory or drive mapping, just recover the entire physical or virtual disk image and you are back in action. Another benefit is this also provides the ability to recover to different hardware platforms. In the past if the server you lost was from one vendor it usually required you to order a duplicate server from the same vendor before you could even begin the restoration process. Now you have the ability to restore entire workloads to any hardware platform or any virtual platform as well.

The same process applies to backing up virtual machines. Don’t get bogged down in selecting which active or inactive virtual machine should be backed up. Select the entire virtual host and forget about it. This way you are assured that you don’t miss that one vmdk or vhd file that is critical to recovering your infrastructure. What if that one virtual disk image was a primary domain controller, active directory or more likely the content server that the SharePoint or IIS database references? Backing up the entire virtual host allows you to set and forget and eliminates the potential of leaving something out of the backup process.

Save yourself some time and don’t think so granular. Select it all and don’t worry at the time of recovery if you are missing something.

Filed under: Backup and Recovery, Best Practices, workload backup | Tagged: , , , , | Leave a Comment »

Back to Basics: Double-Take Software Products and When To Use Them

Posted on June 23, 2009 by brennels

LIVE Webinar: July 22 at 11am ET

The Double-Take Software product line has grown these past few years. And while all of our products work together to provide the leading workload optimization software, there are some important differences between each product. This educational webinar will re-introduce our product line and provide a basic overview of the core features and capabilities. We will also share when to use them based on each business problem.

We will discuss the following Double-Take Software solutions and their related products:

Workload Availability

- Double-Take for Windows and Linux

- Double-Take for Virtual Systems

- Double-Take for VMware Infrastructure

- Double-Take for Hyper-V

- GeoCluster

Workload Backup

- Livewire

- TimeData

Workload Flexibility

- Double-Take Flex

Workload Migrations

- Double-Take Move

Please register for this webinar today!

Filed under: Backup and Recovery, Best Practices, Double-Take Availability, Double-Take Backup, Double-Take Flex, Double-Take Move, Product Information, Webinars | Tagged: , , , , , , | Leave a Comment »

Double-Take 101 Series: Antivirus Tools

Posted on June 22, 2009 by miketalonnyc

Defeating and deflecting virus attacks are becoming a daily part of the IT departments’ activities, and that means antivirus solution sets are becoming an ever-more critical component of the server architectures most of our clients are putting in place. Generally, this doesn’t pose too much of a problem for the Double-Take tool suites, but will occasionally require some settings changes in the event of odd performance problems on the Target device. I’d like to take a few minutes here to discuss why it can happen, and how to avoid/fix it.

Antivirus solutions can use two different types of scanning systems in most cases. They are usually either scan-on-demand or scan-on-access. For many servers, scans are only performed at specific times, using the scan-on-demand method. This doesn’t usually pose any problem for Double-Take, as we’re designed to be able to handle the temporary file locks caused by backup tools, antivirus systems, etc.

With scan-on-access systems, performance degradation on both the Target machine and Double-Take in general can result from the antivirus system attempting to scan every write Double-Take is making to the data. In a traditional one-to-one setup, this will have no more impact on the Target than the same system has processing the application writes to disk on the Source server. However, if you’re using a many-to-one configuration, suddenly the antivirus system must scan multiple times the amount of data on the single Target than it has to contend with on any given Source machine. This can lead to a large amount of system resource overhead, and even cause Double-Take to temporarily disconnect in extreme cases. Of course, Double-Take will reconnect and take the appropriate corrective action, but that’s not something you want to have to deal with on a continual basis.

So, while you shouldn’t need to make many – if any – settings adjustments on the Source for antivirus protection, you may find it necessary to change the way the antivirus systems operate on some Target machines. These settings are not mandatory, but are a best practice, especially in many-to-one configurations.

The most blunt-force method is to turn off antivirus on the Target entirely, but in today’s world that’s just not a practical solution. So instead we can focus on methods used to selectively avoid double-scanning data on both Source and Target, but leave protection intact for all other areas of the file system. Depending on what tools you use for antivirus, you may need to do this at the service level, the file system level, or both.

For service level exclusions, follow the vendor’s instructions for your antivirus system and instruct it to ignore all writes made by the Double-Take Service, or Doubletake.exe. This will allow the scanner to use on-access scans on all other files, but ignore writes made by Double-Take, as these have already been scanned on the Source before transmission. For file-system level exclusions, your antivirus vendor can provide you with instructions to have the system ignore only those directories that contain Double-Take replicated data, and scan everything else.

In either case, on-demand scanning can still be performed on your usual schedule on both Source and Target in nearly all circumstances. Double-Take will continue to replicate changes and if a file is locked for scanning, we’ll queue up data on the Target until the file is freed. At that point we continue writing to the target until we have no more data left to write, or until another lock in encountered. If you suspect that file locking is becoming excessive due to antivirus scanning, simply check the Double-Take log files (in the Double-Take programs directory and with the .dtl extension) in notepad or another text editor. If you see a large number of locked file errors happing very often, you may wish to re-evaluate how the antivirus on-demand scanning is interacting with the replication stream. This is rare, however.

Double-Take products are designed to allow for security to be maintained within an environment both for compliance and antivirus reasons. Adjusting both Double-Take and these security tools will allow for seamless operation of both tool sets.

Filed under: Best Practices, Double-Take Availability, Double-Take Backup, Double-Take Move | 1 Comment »

Double-Take Software: So much more than data replication

Posted on June 22, 2009 by brennels

I read an article the other day that referred to Double-Take software as a data replication product. I didn’t take offense because Double-Take Software has certainly been known as the leader in the data replication, disaster recovery and high availability product of choice for business critical applications like Microsoft Exchange, SQL Server, IIS, Oracle, SharePoint and even protecting virtual infrastructure like VMware VMDK files.

 

But like Bob Dylan album “times are a changing”. Wow, I used the word “album” really showing my age there, good thing I didn’t say 8-track. But times are changing and this year Double-Take Software announced their workload optimization suite that includes so much more than just data replication. The workload optimization suite includes Double-Take Move for full server migrations across hardware platforms, Double-Take Flex for rapid blade and low cost iSCSI provisioning for workstations and servers, Double-Take Availability for the best in class disaster recovery solutions and also Double-Take Backup for full server protection.

Double-Take is so much more that data replication because it can use the core byte level replication engine to move entire workloads across any infrastructure and over any distance. Double-Take has been protecting full server workloads for years now that include the operating system updates, applications as well as the associated data for those applications. Because Double-Take moves the entire workload this provides greater flexibility for porting the workload between physical or virtual infrastructure and even across virtual infrastructures like VMware, Hyper-V and Xen. This provides IT managers with the greatest flexibility to manage their infrastructure regardless of the platform or location.

For more information on Double-Take Software Workload Optimization Suite download a free copy to start moving your workloads. Or check out some Double-Take customers on what they have to say about how easy Double-Take is to use.

Filed under: Backup and Recovery, Workload Optimization, workload backup, workload flexibility, workload migration | Tagged: , , , , , , , | 1 Comment »

The Great Virtualization Management and Migration Tools Race

Posted on June 19, 2009 by brennels

Kevin Fogarty wrote a good article on CIO.com about the race to provide P2V conversion products for the rapidly adopted virtualization market.

“Third-party virtualization companies appear to be taking advantage of what are traditionally slow news weeks in the technology business by rushing out a host of products designed to make virtualization infrastructures more manageable, cheaper, and easier to squeeze into previously unappreciated corners of the IT world.”

Double-Take Software is mentioned in the article as providing a “recoverability twist” to the P2V process by capturing the changes to the virtual disk image in real-time. I wouldn’t refer to this as a twist as much as a significant advantage over other P2V conversion products. The challenge of migrations whether it is server, storage or P2V hasn’t changed over the years. The problem is that most P2V conversion products can not capture the changes to the physical server and replicate those changes to the VMDK or VHD file in real time. Typically once the conversion process starts it only captures that server workload state at that specific time. This either requires IT managers to restrict user access from updating that server once the conversion process is started or trying to apply the differential changes from the time the conversion started to completion which can be several hours.  The objective is still to move the workload (OS, Application and associated data) quickly, without downtime and while capturing all changes made.

The Double-Take Virtual Recovery Assistant feature  now included in the award winning Double-Take Move product provides this function of not only converting a physical server to virtual image but captures all the data changes being made to the physical server so there is no need to prevent user access. Migration no longer have to be conducted during weekends with very small change control outage windows, it can run during production hours and easily failover when ready without user or production interruption.

Filed under: Double-Take Move, Hyper-V, P2V, VMware Infrastructure, Virtualization, workload migration | Tagged: , , , , , , | Leave a Comment »

Dell Puts Customers on Fast Track to Storage Efficiency

Posted on June 16, 2009 by brennels

Dell Puts Customers on Fast Track to Storage Efficiency

Dell Point of View:

Data deduplication is getting significant attention from a growing number of customers looking to manage ever-increasing storage growth by eliminating redundant data. Dell believes data deduplication is just one ? not the only – option to help customers meet this challenge.
Dell is taking a customer-specific approach in which Dell consultants will guide customers in determining how any or all of the following optimization considerations can help them manage their storage as efficiently as possible:

  • Thin provisioning
  • Reclaimed storage
  • Storage virtualization
  • Automated load balancing
  • Data tiering and classification
  • Deduplication

Dell’s deduplication strategy is to foster and encourage the rapid evolution of dedupe technology into a storage environment where the functionality exists everywhere. As deduplication matures quickly, it will move beyond backup storage ? where it primarily resides today — to other data types including near-primary, archive, file and object storage solutions.
Dell believes that incorporating deduplication functionality into ISV, application and storage software can provide significant benefits to customers including:

  • More affordable, better performing solutions than purpose-built appliances.
  • Simplified management through single console interfaces for data protection and management.
  • Reduced network traffic across WAN and LAN infrastructures leading to improved, more cost effective disaster recovery environments.

The News:
Dell now offers a suite of end-to-end consulting services to help customers understand deduplication technology, quantify the benefits, and design a deduplication solution to best meet their needs. Dell’s consulting services are different in that they provide practical, action-oriented plans to deliver specific, predictable and measured outcomes through high-impact, short duration projects.

 Read more how Dell solutions assist with backup and recovery here

Filed under: Backup and Recovery, Best Practices, Dell, Workload Optimization | Tagged: , , | Leave a Comment »

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