Administrators, Start Your Backup Engines ...
The latest in backup software handles the complexity of Windows 2000.
- By Douglas Mechaber
- November 01, 2001
Backup software isn’t the sexiest stuff out there, but it is some of
the most important stuff. A shop that doesn’t have solid backups is asking
for trouble, or, worse, bankruptcy. Choosing the right product is one
of the most important decisions a system or network administrator can
make. It should never be taken lightly, as the repercussions are serious.
Backup software’s been around for ages, but it’s not a static market.
All four of the Windows 2000-aware products evaluated for this article
have been recently revised. If you haven’t looked at the latest software,
it may be time to take another gander at these offerings.
One welcome improvement to the backup process is the recognition that
restoration from scratch is a time-consuming task; all of these products
either have a provision for or include disaster-recovery ability. In an
ideal world, you’d pop in a disk to a recovered server, and the rest of
the rebuild process would be automatic. Things usually aren’t that smooth
(you need a bootable tape drive, such as those manufactured by HP), but
the process has improved over the last few years. What used to be an arduous
task—reloading the operating system, loading the backup software, making
sure that the tape or other device is recognized, restoring an image from
tape—has been abbreviated. Now, after loading a diskette or two, you’ll
typically be able to restore an image with little or no OS or backup software
Win2K brings new challenges to the backup equation. Not only are more
system and application files continuously open (See “Back
up Those Pesky Open Files” for a solution to this issue), but there
are also new file types and system resources that create backup problems.
All the products I looked at handled Win2K system volumes (SYSVOLs), but
when restoring remote servers, information can be lost, particularly if
the backup crosses OSes. NTFS version 5 features—such as catalogs, mount
points or junction points—and advanced features, such as file grooming
or integration with SANs, present additional challenges. Then there’s
the problem of backing up the all-important Active Directory (See “The
Trouble With Active Directory Backups” for some important information
about AD). If you depend on advanced Win2K features (or even if you don’t!)
it’s imperative to verify that you can restore the backed-up information
successfully before you need it.
Reviewed this month:
2000, Advanced Edition
Islandia, New York
(631) 342-6000, esupport.ca.com
Networker for Windows 6.1
Legato Systems Inc.
Palo Alto, California
(650) 812-6000, www.legato.com
6.31 Enterprise Edition
(425) 644-6000, www.ultrabac.com
Exec for Windows NT and Windows 2000 v. 8.6, Server Edition
Veritas Software Corp.
Mountain View, California
(650) 335-8000, www.veritas.com
Which Backup Software for You?
The battle for market share in the backup niche is fierce. Both ARCserve
and Backup Exec offer the ability to read opposing formats, coupled with
the suggestion that switching to their backup product would be a worthy
upgrade. UltraBac boasts impressive speed, efficiency, and easy-to-use
disaster recovery features, while Legato Networker offers the most growth
options for the expanding enterprise.
Which one should you pick? I can’t make the choice for you, but I can
give you a list of the factors to consider:
- Does the software support your backup hardware? Each vendor maintains
a hardware compatibility list on its Web site.
- Do you have special databases (such as SQL Server databases or an
Exchange message store) that need to be backed up? Select backup software
that has an agent for that database, if available, if you need fine-grained
control. Consider using St. Bernard’s Open File Manager, if whole file
backup is satisfactory.
- Do you need support for remote workstations or servers? Licensing
or version options may increase the cost.
- If thinking about changing to a new product, consider: How flexible
is your IT staff? Are they willing or able to learn a new product?
- Is backward compatibility a factor? Can you afford to switch to a
new tape format?
Trouble With Active Directory Backups
If you’ve been backing up your Windows 2000 Domain
Controller regularly, including backing up Active Directory
information, then your domain is safe even if disaster
strikes the server. Right?
Wrong—if you haven’t upgraded your DCs to Win2K
Service Pack 2. The people at Aelita Software uncovered
a nasty bug in Win2K as SP2 was being tested; the bug
was subsequently documented in Knowledge Base article
The problem occurs when a change in AD causes a checkpoint
in the Jet engine used to store the AD information during
a backup. Under those circumstances (which are more
likely to occur the larger your AD becomes), the backup
is corrupted, and restoring it will leave you with a
DC that won’t even boot into AD mode.
Even worse, the problem lies in the native backup API
exposed by Win2K, so it affects all backup software
on the market, Microsoft and third-party alike. Fortunately,
the fix is easy: install SP2, or the hot fix mentioned
in the KB article. Microsoft recommends that you verify
backup functionality and destroy all pre-SP2 backups
that contain AD information.
By the way, when you’re backing up AD you should also
be aware of the issue raised in KB article Q216993 (support.microsoft.com/support/kb/articles/Q216/9/93.ASP).
AD information is timestamped and becomes useless after
60 days. Of course, if you’re not backing up more frequently
than once every 60 days, you’ve got serious problems
with your process anyhow.
up Those Pesky Open Files!
St. Bernard’s Open File Manager solves the substantial
problem of how to handle open files while doing a backup,
without locking users out of applications or creating
a backup where files are out of synchronization. OFM
worked substantially better then the open file agents
included with other backup products and presents many
more configuration options than those agents do.
OFM works automatically and transparently with most
backup software, and a single license includes both
Windows NT/2000 and NetWare versions. OFM works by recognizing
backup read requests for open files. When no partial
file writes are pending, it copies the file to a pre-write
cache. If a file write goes to the portion of a file
being backed up, OFM copies the to-be-changed portion
to the cache, and substitutes that portion when the
backup software asks for the altered sectors. Thus,
the backup has a faithful copy of the file as it looked
when the process started. OFM can be told to release
this cache before or after a verification pass, will
manage groups of files that are updated by a single
application, and will recognize remote backup programs—all
features most other open file agents lack. Another useful
feature lets you use OFM to copy files in use without
doing a backup.
|Open File Manager’s console tracks
backup activity and the files its processing in
real time. You can even alter option settings during
a backup. (Click image to view larger version.)
Using OFM, I was able to back up all the open files
on my system, even ones the open file agents from UltraBac
and BackUp Exec couldn’t handle. OFM does add some overhead,
causing other applications to load more slowly while
it monitored files. The amount of disk space used for
the cache is minimal, because nothing needs to be stored
after the backup’s completed. OFM worked extremely well
and belongs in any installation where application-specific
agents aren’t available, and files are likely to be
left open after hours. One other benefit: because you
don’t have to lock users out of critical files to do
backups, you gain increased backup scheduling flexibility.
Each product I looked at has a clearly different personality and strong
points. ARCserve boasts the most agents and most comprehensive hardware
support. Backup Exec has considerable ease of use and lags only slightly
behind ARCserve in terms of hardware and agent support. UltraBac has the
most innovative features; if you have the patience to understand the job-scheduling
process, it’s a no-nonsense, high-performance product. Legato Networker
is enterprise-aware, reflecting its mainframe roots. It grants ultimate
control over backup and allows authorized users to submit their own backup
and even do their own restore.