Dell PowerVault DL2200 - Manual (Page 7)

tracked and maintained. By default, the file storage location and the Postgres SQL database are installed to the
same location. Right click on the Deduplication Storage Folder in the Backup Exec Device tab and select properties
to access the default settings. The default settings specify 2 concurrent operations for the Deduplication Storage
Folder. The Concurrent operations setting represent the number of backup or restore operations that the
Deduplication Storage Folder will process simultaneously. In addition, the data stream chunk size found under the
Advanced tab for the Deduplication Storage Folder properties can be changed from the default value of 64k. The
data stream chunk size represents the size of each data chunk that Backup Exec writes to disk. While many
customers will be able to use these defaults, some customers may need to change them
Deduplication Database Sizing
Generally, the Deduplication Database is a fraction of the total file storage location size. In Symantec’s testing, the
Deduplication Database increases linearly with total stored deduplicated data. Plan for roughly 6-8 GB of database
size per 1 TB of stored deduplicated data; e.g. 8 TB of deduplicated data would equate to a 50 GB deduplication
database.
Due to periodic weekly database maintenance routines, the PowerVault DL Backup to Disk Appliance requires
double the database size available on disk. This is because automated database maintenance routines involve
making a backup copy of the database. In the example above, where the deduplication database is 50 GB, the
virtual disk holding the deduplication database needs to be at least 100 GB in size to account for maintenance
activities alongside normal operation. The low disk space threshold for the Deduplication Storage Folder can be
used to reserve a minimum amount of space for the database maintenance operations. The low space threshold
can be modified by right clicking on the Deduplication Storage Folder from the Devices tab in Backup Exec. Select
Properties from the pop-up. Select Advanced. The low disk space threshold can be modified from this menu. For
data that gets manually removed, space reclamation is automatically queued for processing twice a day.
Processor Utilization with Client and Media Server Deduplication
Depending on the type of deduplication used, processor utilization will vary. In general, the deduplication process is
not gated or throttled in any way, and is designed to accomplish deduplicated backups and restores as quickly as
possible.
Client Deduplication performs the bulk of the deduplication calculations on the client (or source) system. The client
deduplication process will consume up to one (1) core of one processor on the client system. The actual amount of
processor utilization will depend on the amount of data to be deduplicated and the speed of the processor. Expect
to see at least 75% utilization of the processor core for the duration of the backup.
Media Server deduplication performs the bulk of the deduplication calculations on the PowerVault DL Backup to
Disk Appliance. Similar to client deduplication, the Media Server deduplication process will consume up to one (1)
core of one processor on the PowerVault DL Backup to Disk Appliance. The actual amount of processor utilization
will depend on the amount of data to be deduplicated and the speed of the processor. Expect to see at least 75%
utilization of the processor core for the duration of any Media Server deduplication backup job. For both Client and
Media Server deduplication, initial backup jobs will be the slowest. Backup speeds will increase over time as more
database fingerprints are created.