They offered me $15 Amazon Card for this review

Thanks for taking the time to review Altaro VM Backup. We appreciate your product feedback. It's important to clarify that we are currently offering a gift voucher purely as a courtesy, to thank select respondents for their time should they choose to review us on this site.

In relation to your input about change block tracking (CBT), this is actually a built-in feature on both VMware and Hyper-V. Altaro VM Backup will make use of this hypervisor feature to detect which blocks have changed since the last backup and thus only back up changes, thereby both speeding up the backup job and reducing the amount of data transferred. This feature has no impact whatsoever on the VM, it is already running at hypervisor level.

Regarding concurrency, this is an option which users can toggle on/off depending on the performance of their hardware, particularly their backup device throughput and hypervisor performance. This is a setting which is enabled by default on all of our 40,000+ customers, so we can assure you that it will not cause issues on most devices with decent performance and bandwidth; that said, there are cases when slower devices are being used and concurrency should be switched off to reduce the impact on resources.

Your feedback about error messages is of course dependent on the error you encountered. Our support team would normally recommend a chkdsk in cases where the disk is actually reporting bad blocks/sectors in the Windows (OS) event logs themselves, which of course would make sense. If you believe the incorrect troubleshooting steps were given, we would be more than happy to take another look at your case: Please reach out to suppor@altaro.com quoting the case number and this review, and our team will gladly take another look.

Thanks!