News
1/25/2011
11:32 AM
George Crump
George Crump
Commentary
50%
50%

Deduplication 2.0 - Recovery Performance

"It's all about recovery", you'll here it in almost every sales presentation by a backup vendor. That advice holds true for backup deduplication devices as well. A common mistake is to assume that because deduplication products, most often disk based, that they also offer the best recovery performance. This is not always the case and as we move into the next dedupe era it has to improve.

"It's all about recovery", you'll here it in almost every sales presentation by a backup vendor. That advice holds true for backup deduplication devices as well. A common mistake is to assume that because deduplication products, most often disk based, that they also offer the best recovery performance. This is not always the case and as we move into the next dedupe era it has to improve.A common cause of poor recovery performance seems to be in poor meta data management. Most deduplication systems build some form of a table that tracks what type of data has been written to disk and where it is stored. It is the responsibility of this table to compare new inbound data to data that is already on disk and eliminate the redundant segments. It is also the responsibility of this table, in most cases, to put these segments back together when the backup application requests a file to be recovered. Interestingly as we discussed a while ago in our article "All Deduplication Is Not Created Equal" and what we have seen in repeated testing in our labs is still true today how well this table is managed and accessed can impact recovery performance. In some cases we have seen that the further you get away from the original data set the more of a performance hit poor meta-data management makes.

For example if you do 40 full backups of a data set that changes slightly between sets, meaning that the deduplication ratio is fairly high, and then try to recover from the 3rd copy and then 37th copy. With some deduplication systems you will find a significant difference in the time it takes to recover that data between those two interations of the backup data set. This is certainly something to test in any deduplication system that you are evaluating to make sure your perspective vendor has addressed this issue. It is also something that all deduplication vendors need to keep working on to make sure their systems don't have that problem. Versus straight un-deduplicated disk, a small less than 5%, performance loss is probably acceptable but anything more could begin to significantly impact recovery windows.

The other area where recovery performance is going to become increasingly critical is as data protection solutions continue to add a recovery in place type of capability, as we discuss in our article "Virtualization Powered Recovery". In this instance you can leverage the fact that disk backup technology is in fact disk and running a server instance or other type of data set directly from the backup device is now possible. The performance focus shifts from fast streaming reads to purely random interactive reads. While no one is expecting primary storage like performance, deduplication hardware vendors need to make sure that they can handle this change in requirement from the deduplicated area or they may need to provide a non-deduplicated staging area, to at least keep that performance acceptable.

Another event that impacts recovery performance is what happens when a disk has failed on the backup deduplication system and you need to recover data while the rebuild is underway? We will address RAID data protection and how it is implemented on deduplicated systems in an upcoming entry.

Track us on Twitter: http://twitter.com/storageswiss

Subscribe to our RSS feed.

George Crump is lead analyst of Storage Switzerland, an IT analyst firm focused on the storage and virtualization segments. Find Storage Switzerland's disclosure statement here.

Comment  | 
Print  | 
More Insights
Comments
Threaded  |  Newest First  |  Oldest First
404040
50%
50%
404040,
User Rank: Apprentice
11/16/2011 | 12:25:59 PM
re: Deduplication 2.0 - Recovery Performance
great job
404040
50%
50%
404040,
User Rank: Apprentice
11/16/2011 | 12:26:45 PM
re: Deduplication 2.0 - Recovery Performance
fantastic.
Register for Dark Reading Newsletters
White Papers
Cartoon
Current Issue
Dark Reading December Tech Digest
Experts weigh in on the pros and cons of end-user security training.
Flash Poll
10 Recommendations for Outsourcing Security
10 Recommendations for Outsourcing Security
Enterprises today have a wide range of third-party options to help improve their defenses, including MSSPs, auditing and penetration testing, and DDoS protection. But are there situations in which a service provider might actually increase risk?
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2014-5395
Published: 2014-11-21
Multiple cross-site request forgery (CSRF) vulnerabilities in Huawei HiLink E3276 and E3236 TCPU before V200R002B470D13SP00C00 and WebUI before V100R007B100D03SP01C03, E5180s-22 before 21.270.21.00.00, and E586Bs-2 before 21.322.10.00.889 allow remote attackers to hijack the authentication of users ...

CVE-2014-7137
Published: 2014-11-21
Multiple SQL injection vulnerabilities in Dolibarr ERP/CRM before 3.6.1 allow remote authenticated users to execute arbitrary SQL commands via the (1) contactid parameter in an addcontact action, (2) ligne parameter in a swapstatut action, or (3) project_ref parameter to projet/tasks/contact.php; (4...

CVE-2014-7871
Published: 2014-11-21
SQL injection vulnerability in Open-Xchange (OX) AppSuite before 7.4.2-rev36 and 7.6.x before 7.6.0-rev23 allows remote authenticated users to execute arbitrary SQL commands via a crafted jslob API call.

CVE-2014-8090
Published: 2014-11-21
The REXML parser in Ruby 1.9.x before 1.9.3 patchlevel 551, 2.0.x before 2.0.0 patchlevel 598, and 2.1.x before 2.1.5 allows remote attackers to cause a denial of service (CPU and memory consumption) a crafted XML document containing an empty string in an entity that is used in a large number of nes...

CVE-2014-8469
Published: 2014-11-21
Cross-site scripting (XSS) vulnerability in Guests/Boots in AdminCP in Moxi9 PHPFox before 4 Beta allows remote attackers to inject arbitrary web script or HTML via the User-Agent header.

Best of the Web
Dark Reading Radio
Archived Dark Reading Radio
Now that the holiday season is about to begin both online and in stores, will this be yet another season of nonstop gifting to cybercriminals?