Microsoft’s Azure has promised more speed, lower cache demands and better data retention among a range of improvement to its cloud backup services for enterprise data.

Azure Backup now uses a technology called Update Sequence Number (USN) Journal in Windows to track the files that have changed between consecutive backups. USN keeps track of these changes to files and directories on the volume and this helps to identify changed files quickly.

The upshot of this tweak is a faster backup time. “We’ve seen up to a 50% reduction of backup times when using this optimization,” said Giridhar Mosay, Azure’s Program Manager for Cloud and Enterprise. Individual file server backup times will vary according to numbers and sizes of files and directory structure, Mosay warned.

A new algorithm that computes metadata has slashed the amount of cache space needed for each Azure Backup by 66%. The standard allocation of 15% cache space per volume size being backed up to Azure has proved prohibitive for volumes greater than 10TB. The new algorithm makes the cataloguing of the file space to be backed up a much more efficient process, which creates so much less metadata that it demands only 5% cache space, or less. Azure is now modifying its requirement for cache space to a third of the old level.

Meanwhile the resilience of the system has improved as Azure Backup has increased the number of recovery points for cloud backups. This allows for flexible retention policies to meet stringent compliance requirements such as HIPAA (the federal Health Insurance Portability and Accountability Act of 1996) for large enterprises. The new maximum number of recovery points has increased from 366 to 9999.

Other tweaks include more timeouts across the various phases of backup process to ensure that long running jobs complete reliably. Cloud backups will also run a bit more efficiently as a result of a decoupling of the processes of cataloguing and uploading the backup data. Intermittent failures, in the service to handle incremental backups, have also been identified and resolved, according to Mosay. “We are continuing our journey to make Azure backup enterprise grade,” he said.