HPE Data Protector stores multiple backup objects on a single Catalyst store item. A backup object can be a volume, a mount point, a database or a virtual machine. You can have multiple backup objects per backup client. If your filesystem backup job has four backup clients, and each client has two volumes, the backup job will contain 8 backup objects. Another example is a single database of a Microsoft SQL or Oracle database server (instance).
A Catalyst store item is an object of a StoreOnce Catalyst store and stores the data of a specific backup job. If you backup multiple VMs in a single VE Integration job, the Catalyst store item will include all VMs from that specific job. Or if you backup an Exchange server with three databases, the Catalyst store item is used to store these three databases. Due to this behavior, a single Catalyst store item can reach enormous sizes. Usually this is not a problem. But if you have to copy backup objects to other media (e.g. tape), Data Protector has to read the store medium for each backup object. As the name says: The copy operation in Data Protector is based on backup objects. If there are multiple backup objects on a Catalyst store item, a backup object copy can take some time.
Since HPE Data Protector 8.1, Data Protector offers an option to store a single backup object per Catalyst store item. You can enable this option in the properties of a StoreOnce D2D device (“Settings” tab).
With this option, Data Protector will create a single Catalyst store item for each backup object. This option can significantly speed up object copy operations. You should consider this option in the following cases:
- You have to speed up object copy operations
- You have multiple large backup objects per backup client (e.g. Exchange with multiple large databases, Microsoft SQL server with multiple large databases, VMware/ Hyper-V backups, file servers with large volumes etc.)
A possible disadvantage is the increasing number of Catalyst store items, especially if you have a large number of backup clients with many small backup objects. HPE Data Protector and StoreOnce have a limit with regard to the maximum number of Catalyst store items (which isn’t publicly documented …).