Consider drive imaging for disaster recovery
Wednesday, August 02, 2006 02:40 PM
If you are shopping for a low-cost disaster recovery solution, you might want to consider drive imaging as an alternative. Jerry Templado offers his experience with Symantec Ghost and Acronis True Image.
Finding the ideal disaster recovery (DR) solution can be a daunting task, and even more so when faced with tight budget constraints.
As a consultant, it has been my experience that a lot of the "old school" IT professionals have a tendency to lean toward tape backups, utilizing a variety of platforms ranging from NetBackup to ARCserve to Backup Exec, and everything in between.
Those products are all great solutions, but when you examine the costs of implementation and management, you might see your budget dwindle fairly quickly. In addition to the potentially higher operating cost, you're faced with the complexity of the software platform. You almost need to have a DBA or a DR specialist on staff to adequately manage some of these solutions, and for small businesses, that's not likely to be in the budget. With these issues in mind, I would like to recommend an alternative DR solution that takes advantage of drive imaging technology.
You're probably thinking, "Isn’t that what they use for those recovery disks that ship with PCs?" The answer is yes, but that technology can also be a much cheaper alternative for DR, especially now that drive-imaging technology has become a competitor of the well established tape-driven DR solutions applied on an enterprise scale.
Drive imaging as a DR solution is well worth considering, especially when you look at the costs of implementation and the relative simplicity of the software. There are two products that I have had a great deal of success in using: Symantec Ghost Enterprise Edition 7.5 and Acronis True Image Enterprise Server 9.1. You may be familiar with Symantec Ghost and its primary application for desktop PCs, but it is also very useful on servers. For those who have not heard of Acronis True Image, it is a backup software that works much like Ghost in that it makes images of the drives or data sets that you are backing up, and has extended capabilities that make it a complete DR solution.
Should you consider Symantec Ghost as your DR solution?
There are a few key issues to consider before you make a
decision about the DR solution to deploy. You need to examine the number of
servers, the key role of these servers, and how current the backed up data
needs to be. If your network infrastructure is comprised of a relatively small
number of servers with a fairly static database and little change over the span
of time between backups, then Symantec Ghost would be an ideal solution.
Backups can be performed locally on the machine from disk-to-disk, or across
the network to a network share, using the GhostCast Server application and a
bootable disk or CD for the GhostCast client. You will need to take the server
out of production in order to perform your backup, so this operation will not
harm an Oracle or SQL database. The cost of management would be well worth the
expense, and you could easily archive the images to DVD-Rs, which are a
fraction of the price of most tape cartridges. One of the aspects of backing up
with Symantec Ghost is that if the image exceeds 2 GB, then it starts to span
the images into 2-GB portions. That makes it easier to offload images from your
storage location should you need to free up some space.
Symantec Ghost will also install on Windows 2000/XP, sparing you the added cost of building a separate server. You can actually get away with just copying the GhostCast Server executable and running it on a laptop with Windows 2000/XP. You can then take it to a remote location to back up a server, so as to spare your bandwidth across WAN links, and later upload the image to a network share. DR is just as simple a process as the initial "ghosting" of your disk image, and Ghost has an application called Ghost Explorer, which allows you to explore and image, and extract files as needed in the event that you must restore individual files.
Ghost is also a great tool for multiple server builds, and can save you a lot of time. In this application, you just back up the first completed server, and restore or--as Symantec likes to refer to it--"ghost" it to the other servers. There are some caveats, however, to using Ghost in this way. Microsoft doesn't recommend it, because each ghosted machine is an exact copy of the original, and you will run into issues with duplicate computer SIDs. Microsoft's Sysprep utility can fix that issue, but they suggest you perform that task prior to ghosting. Also, should the need to recover from a catastrophic server failure occur, there are some limitations to Symantec Ghost: Symantec does not support restoring the image to a dissimilar machine. This does not mean it can't be done, but it isn't a part of Ghost's normal operation. Performing backups with Symantec Ghost is a manual process, which hinders any attempts to automate it. While I would not necessarily knock the application of Symantec Ghost as a DR solution, I do think you should be aware of its limitations.
Acronis True Image extends your options for DR
Now, if you are in the market for a more complete solution, then
Acronis True Image Enterprise Server 9.1 would be a great candidate, regardless
of the size of your network. True Image is a simple and versatile platform to
employ as your DR solution and installs on many different platforms. You aren't
restricted to running True Image Backup Server on just server-class operating
systems, and it can be installed on almost the entire family of Windows
operating systems, including the 64-bit versions. The backup agent supports all
current versions of Windows workstations and server-class operating systems, as
well as many flavors of Linux.
Flexible storage media
True Image supports hard disks; tape drives; USB 1.0/2.0 and
FireWire devices; SANs and NAS; ZIP and Jazz drives; FTP servers; and CD-R/RW,
DVD+R/RW, and DVD-R/RW. At this time, you will need third-party CD/DVD
recording software, but according to a member of Acronis' marketing department
that I contacted, Acronis is currently developing that feature and will make it
available as a free update in the future.
Data consistency and
continuity
Unlike Symantec Ghost, Acronis True Image can make disk images
while the machine is live, so it does not need to be taken out of production. With
Windows Server 2003 Volume Shadow Copy Service support, you can back up VSS-compatible
databases such as Oracle, Exchange, and SQL Server without having to take them
offline, which ensures data consistency and continuity. This is an especially
great feature for a server that you can’t afford to have offline. With the
management console, you have a great deal of control over the kinds of backups
you want to perform, and flexible scheduling capabilities to ensure good
continuity of data.
Flexible backup
scheduling
With Acronis True Image, you can perform three levels of
backups: Full, Incremental, and Differential. You can back up individual disks
or all disks (into a single image), and you can even back up individual files
and folders, or exclude certain files and folders. In the management console, you
have the ability to schedule your backups on a daily, weekly, monthly, and
yearly basis. You can also choose to schedule each server individually, or as a
group. You have control over the backup priority, so you can minimize the
impact of other services running on a particular server or throttle the amount
of bandwidth to minimize impact on your network.
There is even the ability to password-protect your images, and send pre- and post-data capture commands, such as unmounting and remounting the database that is being backed up. You can set the level of image compression, and split archives to limit the maximum size of each image portion--allowing for easier management and storage to smaller-capacity storage media.
Automation options
You can completely automate the management of your archives using
the task-scheduling tool, as well as some of the archive maintenance tasks by
setting quotas and time limits. Depending on your retention policies, you have
the ability to set time limits on how long archives are kept and can have them
deleted once they expire; and with quotas, you can set the maximum number of
full, incremental, and differential backups that are kept.
Recovering files and
servers
Recovery of files or an entire system with True Image couldn’t
be any easier. Right-click on the archive you wish to restore or "mount"
that archive as a virtual drive and use Explorer to navigate through it like
any other drive. The recovery capabilities are what really set True Image
apart, because you can perform a bare-metal recovery and have the server back
up and running in minutes, even while True Image is still restoring that
server. There is also a utility included to make bootable disks for systems
that have become unbootable.
With Acronis Universal Restore, you have the ability to restore to servers with dissimilar hardware. Unlike Symantec Ghost, Acronis automatically detects the machine type and installs the appropriate drivers for HAL, which is something of a tedious task to do manually in Ghost. Acronis also allows you to add drivers during recovery, making for a more complete restore, and it has a centrally-stored driver repository so that you won’t have to go looking for those drivers again.
Summary
While Symantec Ghost can give you a good, basic DR solution
for a small-business environment, Acronis True Image Enterprise Server 9.1 is a
complete package for DR for any size network. With its robust platform and simple
management interface, it makes the daunting task of implementing and
maintaining a good DR plan much less of an ordeal.
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