Change Tracking gets the most from Hyperoo and your hardware
Whilst many of you will be happy with the Standard Backup mode available in Hyperoo Free Edition, it can become cumbersome and time consuming for more demanding scenarios. Enter Change Tracking, Hyperoo’s advanced backup mode which will dramatically speed up your backup and substantially reduce the load on your servers!
To understand the benefits of Change Tracking it first helps to know how Hyperoo runs a backup in Standard Backup mode.
Standard Backup
For very large files, such as virtual hard disk files (.vhd/.vhdx), the difficulty with backups is transferring a large amount of data over the network in an acceptable time window. For most scenarios network speeds tend to be the bottleneck when copying data and writing it to the destination server. If we can keep network traffic to a minimum then we can also reduce backup times.
To reduce the amount of data sent over the network Hyperoo compares the source and backup files to determine which parts of a file need to be backed up. The backup server receives changed data and writes it to the backup files resulting in identical files on the host and backup server. The comparison algorithm is inspired by rsync, a tool widely used on Unix/Linux systems.
When backing up large files, the period spent comparing files can itself be a time consuming process. It is still faster than simply transferring the whole file for each backup, but if you are backing up several hundred gigabytes of data on a busy host with heavily contended disk I/O, the time taken to compare files can run into several hours, even if the amount of changed data is small.
The diagram below shows the process used in Standard Backup mode. The vertical size of the boxes is used to give an indication of how much time is spent on each activity. The diagram assumes a typical Hyper-V backup where the vast majority of data is in virtual hard disk files.
As you can see, a significant portion of the backup time is spent reading the source and destination files. Quite often the backup server is of a lower specification than the backup client which can significantly extend the backup time during which the client machine waits for it to catch up. The process of reading the files is I/O intensive and puts additional load on disks during this period.
If Standard Backup turns out to be too lengthy or too resource intensive for your requirements then Change Tracking is a more attractive alternative.
Change Tracking Mode
To avoid the need to perform lengthy file comparison operations, Change Tracking monitors and records all modifications to the files being backed up by Hyperoo. This data is stored in a change log for each backup task. When the backup runs, the change log is used to calculate which parts of a file have been modified since the last backup.
The diagram below shows the process for a Change Tracking backup. As before, time is indicated by the vertical size of the boxes for each activity.
Notice the difference? Change Tracking takes considerably less time. It also consumes much less disk I/O because there is no requirement to read and compare files. You can run backups more frequently knowing that Hyperoo is not going to hog precious server resources.
Conclusion
Change Tracking is FAST! If you are backing up Hyper-V, Exchange or any application with very large files it should be your preferred option. Change Tracking will ensure you are getting the most from Hyperoo and your hardware.
