Talk:Disk-based backup

Backup-to-Disk

Backup-to-Disk (B2D) is technology that allows one to backup large amounts of data to a disk storage unit. The backup-to-disk technology is most often supplemented by tape drives for data archival or replicated to another facility for disaster recovery. Backup-to-disk offers several advantages, both technical and business, to traditional tape backup. The storage devices continue to be faster and offer higher storage capacity. As these units continue to improve backup-to-disk will become more prominant in organizations.

Technical Advantanges

There are many technical advantages to backup-to-disk technology. One of the main advantages is the speed at which backups can be performed to the disk appliance. Backing up data to a backup-to-disk technology can be up to four times faster than traditional SCSI tape devices. While the new Serial Attached SCSI (SAS) connected tape drives are faster than the original tape drives, the disk appliance is still faster than most tape technologies. These faster backup times lead to shorter backup windows allowing the technology to backup the data while in a smaller amount of time thus increasing the window for processing which is also a benefit for the business.

Another advantage that backup-to-disk offers is data de-duplication and compression. The disk appliances offer either de-duplication at the source or at the destination. The de-duplication at the destination is faster and requires less performance overhead on the source host. The de-duplication requires less disk space on the disk appliance as it stores only one copy of the possible multiple copies of one file on the network.

Many of the backup-to-disk technologies advertise up to 15 to 1 compression ratios. This also allows the information technology department to store more data on less disk space. With de-duplication a disk appliance with 5 terabytes of raw disk space and store as much as 30 terabytes of compressed and de-duplicated data.

One the biggest advantages to disk backup is reliability. There have been studies that show that 70% of tape restores fail. The disk appliance will eliminate tape errors which will improve the success of both backup and restore jobs.

Business Advantages

Disaster Recovery

The most important advantage that backup-to-disk provides for the business, and for the technology department, is faster recovery of the data. Most businessed today have several terabytes of data that the business must be able to retain in the event of a disaster. This disaster can be as simple as server hardware failures to as severe as a regional disaster, such as a natural disaster. For the localized disaster the disk appliance allows the technology department to hold one or two weeks of backups, depending on the size of the disk appliance and the amount of data being backup, which allows for very quick recovery.

Business Continuity

The larger disasters must follow the organizations Business Continuity Plan. The business will set forth the guidelines for which systems must be online with a set number of days. With a backup-to-disk system the technology can replicate the backups to a second device at another location. This can be beneficial if the organization has another location in which they intend to recover their systems in the event of a large disaster. Backup-to-disk technology can greatly benefit an organization in continuing to do business should a disaster damage their facilities and technology.

Products

There are several Disk Backup solutions on the market today. Below are a few of the industry leading devices.

EMC

EMC offers two disk backup devices for its customers. The first is the original EMC offering the Avamar. The Avamar unit de-duplicates the data at the source via an agent on the host which offers savings on bandwidth utilization during backup. Please see EMC's website for details.

The second EMC offering is the Data Domain device which EMC aquired from Data Domain in 2009. The Data Domain device de-duplicates the data at the destination which reduces the overhead on the host. Please see EMC's website for details.

Both of these units offer site-to-site replication.

Quantum

Quantum offers several models for disk backup solutions. The DXi-V series is an entry-level unit that stores from 1-2TB of data. This unit is great for small businesses.

The midrange level units are the DXi4000 and DXI6000series. The DXi series is scalable allowing the technology department to add more units as data grows in the organization.

The enterprise level unit is the DXi8500. This unit is ideal to anchor an enterprise backup solution and data protection strategies.

All of the offerings from Quantum have de-duplication, compression, and remote site replication. Please see the Quantum website for details.

References

1. Gardner, S., Disk to Disk Backup vs. Tape - War or Truce?, Retrieved May 28, 2012
2. EMC Avamar, Avamar Family - Backup and Recovery, Retrieved May 28, 2012
3. EMC Data Domain, EMC Data Domain Family - Backup and Recovery, Retrieved May 28, 2012
4. Quantum Disk Backup Systems, http://www.quantum.com/Products/Disk-BasedBackup/index.aspx, Retrieved May 28, 2012
5. Eversync, Disk verses Tape, Retrieved May 28, 2012
6. Shinder, D., Disk Based Backup: All Hype or the Best Protection for your Data?, Retrieved May 28, 2012