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

• Tape drive emulation types have no effect on performance or functionality
• Configuring multiple tape drives per library enables multi-streaming operations per library for
good aggregate throughput performance.
• Do not exceed the recommended maximum concurrent backup streams per library and
appliance if maximum performance is required.
• Target the backup jobs to run simultaneously across multiple drives within the library and
across multiple libraries. Keep the concurrent stream count high for best throughput.
• Create multiple libraries on the larger StoreOnce appliances to achieve best aggregate
performance
• Configure dedicated Individual libraries for backing up larger servers.
• Configure other libraries for consolidated backups of smaller servers.
• Separate libraries by data type if the best trade-off between deduplication ratio and
performance is needed
• Cartridge capacities should be set either to allow a full backup to fit on one cartridge or to
match the physical tape size for offload (whichever is the smaller)
• Use a block size of 256KB or greater. For HP Data Protector and EMC Networker software
a block size of 512 KB has been found to provide the best deduplication ratio and performance
balance.
• Disable the backup application verify pass for best performance.
• Remember that virtual cartridges cost nothing and use up very little space overhead. Don’t be
afraid of creating “too many” cartridges. Define slot counts to match required retention policy.
The D2DBS, ESL and EML virtual library emulations can have a large number of configurable
slots and drives to give most flexibility in matching customer requirements.
• Design backup policies to overwrite media so that space is not lost to a large expired media
pool and media does not have different retention periods on the same piece of media.
• Reduce the number of appends per tape by specifying separate cartridges for each incremental
backup, this improves replication performance and capacity utilization.
Summary of VTL best practices 69