In Acronis Backup & Recovery 11 (Build 17437 or later) and Acronis Backup & Recovery 11.5 use this solution:
Starting from this builds Acronis has implemented pre allocation ability, so the data store files increased with large portions of data, so it has less fragments. The default pre allocation size is 512 MB. For large data store size (e.g. 11 TB) this is not enough. You need to adjust the pre allocation size manually according to the data size planned to be stored in the vault.
To set up pre allocation size follow these steps:
Go to Start -> Run -> services.msc -> and stop Acronis Storage Node service;
Go to Start -> Run -> regedit.exe to open Windows registry editor and navigate to this key:
Change the default value (is 512 in megabytes). If you plan having more than 10 Tb of unique data size it’s recommended to set PreallocatedDatastoreIncrementSize to 1024;
Go to Start -> Run -> services.msc -> and start Acronis Storage Node service;