By Heidi Biggar
A recent InfoStor reader survey appears to back vendor claims that disk-based backup has shed its “early adopter” status and is being more broadly implemented by users to protect growing data volumes.
Of the 116 users polled, 45% said disk was their primary backup/recovery target, while 46% said they relied primarily on tape and some disk. Only 17% of respondents said they used tape exclusively (see figure).
Nearly half of the users polled (49%) said they had already implemented disk-based backup in some form (e.g., virtual tape, NAS, disk-based targets, etc.), and another 28% said they planned to implement disk-based backup within the next 18 months.
Although these numbers aren’t significantly higher than those in a similar InfoStor reader survey conducted about a year ago, there are some notable differences that indicate the increasing maturation of the disk-to-disk (D2D) backup market. (For example, 85% of respondents to the 2004 survey said they thought of disk-based backup as an “evolving” technology.)
In particular, while users still prefer to do disk-based backup at the backup application level (e.g., leverage disk-based backup options available in standard backup applications), they are significantly more likely to implement disk-based targets or virtual tape libraries (VTLs) today than they were a year ago.
As a point of comparison, while 51% of respondents to the 2004 survey said they would “experiment with new [backup] technologies for certain applications,” 44% of respondents to the 2005 survey said they had either already implemented disk-based targets or planned to implement them in the next 12 months; similarly, 33% said they had either already implemented or planned to implement VTLs.
In contrast, more users (19%) said they used NAS for backup-specific purposes than either ATA/SATA disk arrays (16%) or VTLs (13%). While use of NAS as a backup target dropped slightly in the 2005 survey (to 16%), analysts say users may increasingly implement VTLs in combination with NAS targets for improved backup-a trend hinted at by Network Appliance’s acquisition of VTL provider Alacritus last month (see “NetApp banks on VTL, buys Alacritus,” InfoStor, May 2005, p. 16).
Analysts say that “front-ending” a NAS filer with a VTL can help users address issues with pure NAS backup approaches (e.g., backup application support, performance, and tape creation for disaster-recovery purposes) without sacrificing any of the benefits.
In addition to increasing support for disk-based backup, the recent InfoStor survey revealed strong user interest in, and adoption of, replication and snapshots, newer technologies such as continuous data protection (CDP), and compression. These findings suggest that users are increasingly relying on a continuum of data-protection tools, rather than a single backup approach (e.g., tape), to meet their varied backup requirements. Matching backup tools to specific data requirements (e.g., recovery time/point objectives) can help users ensure a cost-appropriate, reliable backup-and-recovery process.
About 62% of respondents to the 2005 InfoStor survey said they had either already implemented, or planned to implement within the next year, replication, while 51% had already implemented or planned to implement snapshots. Respondents also showed significant interest in compression and continuous data capture, although few products are available at this time.
Users can expect to see significant improvements in compression capabilities-in particular, from VTL vendors-over the next six months as well as increasing availability of CDP products. According to analysts, CDP has the potential to “revolutionize” the recovery side of the data-protection equation (see “Early adopters praise CDP,” InfoStor, May 2005, p. 10).
As for backup-and-recovery issues, 50% of the survey respondents said hardware/software costs were their biggest issues; however, backup efficiency (e.g., tape/disk utilization), backup speed (e.g., inability to complete backup jobs in the allotted window), recovery abilities, and people costs were also significant factors.
However, from a purchasing standpoint, respondents said cost (66%), reliability (65%), and backup speed (62%) were the leading influencers/deterrents. Ease of use (54%), recovery speed (51%), and capacity (51%) were also significant factors; less important were vendor name/reputation, compliance-related issues, and media removability.
Finally, while 91% of users said that less than 10% of their backups fail on a weekly basis, 31% said that although they were confident that their data is backed up properly they are not sure they would be able to recover it.