Backup data reduction is not an easy task, particularly for SMBs. Data deduplication and compression can reduce backup data by 90 percent or more, and thus reduce hardware and management costs. But SMBs often have a lack of hands-on experience using these technologies and can use the help of an IT storage service provider.
In this Q&A reprinted courtesy of BridgeSTOR, get answers to the most frequently asked questions your customers might ask about backup data reduction services.
1. Should we use deduplication, compression, or both?
Both. Deduplication and compression work independently and are complementary technologies that together can provide data reduction of up to 90 percent. Used alone, either can be effective at reducing disk backup capacity requirements, but an overall data reduction strategy includes both deduplication and compression. If you achieve 2:1 compression of backup data that has already been deduplicated by a 10:1 ratio, the result is a total data reduction ratio of 20:1.
2. What is best – hardware-based or software-based data reduction?
There are reasons for your customers to consider both, but compression in particular requires processing power, so it impacts backup performance least when it is deployed as a hardware-based solution. Hardware-based data reduction appliances also offer the advantage of compatible pre-configured applications, rather than a piecemeal collection of products that your customers must purchase, install, configure, and manage themselves. Look for data reduction appliances that do not require a separate backup server, which adds complexity and increases the overall cost of the backup infrastructure. An all-in-one backup data reduction appliance takes the guesswork out of implementing multiple solutions.
3. Tape backup systems include compression; why can’t we use hardware compression on my disk backup system?
Disk compression has traditionally been file-based. Hardware compression works on data blocks, not files. Until recently, the challenges of implementing block-based data compression on disk have been insurmountable. That is now changing with the introduction of data-reducing backup appliances equipped with hardware-based disk compression.
4. What about backups of remote servers, or backups that are sent offsite for disaster recovery purposes?
Backup data reduction must address backing up the servers at HQ as well as remote offices, and sending backup data to a disaster recovery (DR) site. Backup should be a single, continuous process, centrally and conveniently managed, which is possible with data reduction appliances.
5. Can the same data reduction appliance for backup data be used for primary data?
Typically, deduplication and compression are applied to primary data in very different ways. Primary storage deduplication works on blocks of data aligned at the disk’s boundaries. Windows and Linux file systems align the beginning of each file at the beginning of a block. This means that primary storage deduplication will always identify duplicate blocks within files. Also, databases read and write on fixed-size pages, so duplicate data within a single database or across databases can be detected. Backup applications, on the other hand, create files that are the equivalent of .tar or .zip files in which the blocks are not always aligned the same way, so backup deduplication applications have a very different job to do than primary data deduplication.
6. Why do data reduction solutions vary so much in price?
Just comparing prices won’t provide a true apples-to-apples evaluation. A better metric is the cost per terabyte of backup to disk capacity. How many concurrent backup streams are supported? What is the impact on backup performance, if any? The wrong answers to these questions will actually cost your customers more even at the lower entry price point.
