This article can also be found in the Premium Editorial Download "Storage magazine: Top features in data backup applications."
Download it now to read this article plus other related content.
CommVault's Simpana deduplication facility is difficult to categorize as target or source dedupe. Deduplication in backup software requires multiple steps: (1) slicing files to be backed up into segments or "chunks"; (2) creating a "hash" value (typically using SHA-1); (3) doing a hash table lookup to see if the value is unique; and (4) deciding whether or not to send the chunk to storage. Source deduplication products perform all four steps on the client; target deduplication appliances do all four at the target or backup server. With CommVault's approach, however, steps one and two are done at the client while steps three and four are done at the backup server (media agent in CommVault lingo). This is why it's difficult to classify the dedupe as source or target.
But if the real distinction between the two categories is whether or not the original, native data ever leaves the client, then CommVault Simpana is best placed in the target deduplication category. Still, Simpana's unique practice of doing the first two steps on the client allows it to do something other target products can't do: client-side compression. Most target dedupe systems won't deduplicate your data well if you compress it at the client before sending it to the target because compression inhibits the deduplication system's ability to correctly chunk and fingerprint the data to identify duplicates. But because Simpana chunks and fingerprints the data at the client, it can compress it before sending it
Data protection management: Beyond simple backup stats
Data protection management (DPM) was introduced several years ago by Bocada Inc., the first company to attempt to produce standardized reports on multiple backup products. A number of other startup firms soon entered the fray, including Aptare Inc., Tek-Tools Software Inc. (recently acquired by SolarWinds, Inc.), TSMworks Inc., Servergraph (now part of Rocket Software Inc.) and WysDM Software (now part of EMC). The big backup software vendors saw the potential of the DPM market: Symantec picked up a product called Advanced Reporter, which became Veritas Backup Reporter and then later Symantec's OpsCenter Analytics line; and EMC turned the WysDM product into its Data Protection Advisor.
All of these products offer far more than simply telling you which backups worked and which didn't, functionality that many believe should be included in any decent backup software. However, when it comes to things like trending, capacity planning, cross-product reporting and issues that go beyond traditional backups, standalone DPM products have carved out a unique niche.
Backup apps have begun to incorporate some of these capabilities. CommVault, in particular, has been vocal about how these reporting tools should be included in the base backup product. While it could be argued that the reporting included in Simpana is better in some areas than the reporting in other companies' base products, that's not to say Simpana users couldn't benefit from a DPM product. For TSM customers, IBM's response has typically been that everything you need to know is in the TSM database so you just have to run a query. While that's true, it might be beyond the capability of many users. So while a few of the big backup vendors have incorporated some DPM features, users who need full data protection management functionality will likely turn to a third-party product.
Continuous data protection: Still kicking
Only a few years ago there were a number of companies with continuous data protection (CDP) applications, but many of them are no longer around. Some simply went out of business, while others were acquired in fire-sale deals. Did CDP simply not work? Was it a bad idea? Or was it the Star Trek of backup products (a great idea before its time)?
CDP's rise and fall was probably a combination of all of the above. When CDP works as advertised, it's easily the best way to protect your most critical applications: zero downtime for backups, and recovery time objectives (RTOs) and recovery point objectives (RPOs) of zero. What's not to like? Unfortunately, storage managers tend to be most risk averse when it comes to their mission-critical applications, so few users opted to back up those mission-critical applications using a completely different method from a vendor that they'd never heard of before.
But attitudes toward CDP changed when major companies got into the game. Symantec bought Revivio and eventually released NetBackup RealTime. IBM came out with Tivoli Continuous Data Protection for Files and bought FilesX, which became TSM FastBack. EMC purchased Kashya and delivered RecoverPoint. CommVault built its own CDP functionality around its core Common Technology Engine. With these key players in the CDP game, users can now try it in their own environments without the fear that their CDP vendor may go out of business tomorrow.
This was first published in March 2010