7 Performance
Optimizing peformance
In order to optimize the performance of your system and minimize the likelihood of StoreOnce
operations competing for processing resources it is important to understand the complete workload
being placed on the HP StoreOnce Backup System. The following is a very brief overview of factors
to be considered. We strongly recommend that you read HP D2D Backup Systems best practices
for VTL, NAS and Replication implementations that is available on
http:www.hp.com/support/
manuals
for more detailed guidance.
StoreOnce key processes
Key processes are:
•
Backup with deduplication
•
Replication
•
Housekeeping
By default replication will start quickly after a backup completes, this window of time immediately
after a backup may become very crowded if nothing is done to separate tasks. In this time there
are likely to be other backups to the StoreOnce Backup System which have not yet finished and
there will be housekeeping of deleted and overwritten data.
How to avoid overlaps
These operations will all impact each other’s performance, some best practices to avoid these
overlaps are:
•
Try to schedule backups so that they finish at the same times, this may take some trial and
error. If all backups can run in parallel there is an overall aggregate performance increase
and if they finish within a few minutes of each other, the impact of housekeeping from the
backup jobs will be minimized.
•
Set replication blackout windows so that replication does not overlap with backup and
housekeeping.
•
Set housekeeping blackout windows so that housekeeping does not overlap with backup and
replication.
For more information
Each of the key processes is described in more detail in this guide. For information about using
the Web Management Interface to schedule backups, replication blackout windows and
housekeeping blackout windows, refer to the HP StoreOnce Backup System user guide.
Balancing performance and deduplication ratios
If you are using one of the flexible emulation types, it is important to balance the pool of devices
carefully. In this context, a device may be a NAS share or a VTL loader or tape drive.
Best deduplication performance is achieved by having as few Stores as possible, so you would
configure multiple tape drives to a single VTL device.
Best performance is achieved by having concurrent streams across multiple stores, providing a
one-to-one host/store relationship.
To use the HP D2D4312 as an example:
•
Writing 24 streams to 24 separate libraries provides the best performance.
•
Writing 24 streams to 24 drives on a single library provides the best deduplication ratio.
40
Performance
