HP StoreOnce Backup System Concepts and Configuration Guidelines (BB877-90913, November 2013)

10 NAS shares
NOTE: It is important to understand that the HP StoreOnce network share is intended to be used
ONLY by backup applications that “back up to disk”. Do not use the NAS target device as a
drag-and-drop general file store. The one exception to this rule is if you are using the NAS share
to seed an appliance for replication.
Operating system support
Two interfaces are supported:
• a CIFS interface for Windows networks
• a NFS interface for Linux and UNIX networks
See the HP StoreOnce Backup System user guide for more information about using the Web
Management Interface to create and configure NAS shares as targets for backup applications.
Refer to the UNIX and Linux Configuration Guide for more information about the NFS interface.
Backup application support
NAS shares may be used with most applications that support backup to disk, including embedded
applications, such as Oracle RMAN and VMWare VCB Agent. For the most up-to-date information
about supported applications, refer to http://www.hp.com/go/ebs.
Shares and deduplication stores
Each NAS share created on the StoreOnce system has its own deduplication “store”; any data
backed up to a share will be deduplicated against all of the other data in that store, there is no
option to create non-deduplicating NAS shares and there is no deduplication between different
shares on the same StoreOnce appliance.
Once a StoreOnce CIFS share is created, subdirectories can be created via Explorer. This enables
multiple host servers to back up to a single NAS share but each server can back up to a specific
sub-directory on that share. Alternatively a separate share for each host can be created.
The backup usage model for StoreOnce has driven several optimisations in the NAS implementation
which require accommodation when creating a backup regime:
• Only backup files larger than 24 MB will be deduplicated, this works well with backup
applications because they generally create large backup files and store them in configurable
larger containers . Please note that simply copying (by drag and drop for example) a collection
of files to the share will not result in the smaller files being deduplicated.
• There is a limit of 25000 files per NAS share, applying this limit ensures good replication
responsiveness to data change. This is not an issue with many backup applications because
they create large files and it is very unlikely that there will be a need to store more than 25000
on a single share.
• A limit in the number of concurrently open files both above and below the deduplication file
size threshold (24 MB) is applied. This prevents overloading of the deduplication system and
thus loss of performance.
When protecting a large amount of data from several servers with a StoreOnce NAS solution it is
sensible to split the data across several shares in order to realise best performance from the entire
system by improving the responsiveness of each store. Smaller stores have less work to do in order
to match new data to existing chunks so they can perform faster.
The best way to do this whilst still maintaining a good deduplication ratio is to group similar data
from several servers in the same store. For example: keep file data from several servers in one
share, and Oracle database backups in another share.
70 NAS shares