NetBackup™ Backup Planning and Performance Tuning Guide
- NetBackup capacity planning
- Primary server configuration guidelines
- Size guidance for the NetBackup primary server and domain
- Factors that limit job scheduling
- More than one backup job per second
- Stagger the submission of jobs for better load distribution
- NetBackup job delays
- Selection of storage units: performance considerations
- About file system capacity and NetBackup performance
- About the primary server NetBackup catalog
- Guidelines for managing the primary server NetBackup catalog
- Adjusting the batch size for sending metadata to the NetBackup catalog
- Methods for managing the catalog size
- Performance guidelines for NetBackup policies
- Legacy error log fields
- Media server configuration guidelines
- NetBackup hardware design and tuning considerations
- About NetBackup Media Server Deduplication (MSDP)
- Data segmentation
- Fingerprint lookup for deduplication
- Predictive and sampling cache scheme
- Data store
- Space reclamation
- System resource usage and tuning considerations
- Memory considerations
- I/O considerations
- Network considerations
- CPU considerations
- OS tuning considerations
- MSDP tuning considerations
- MSDP sizing considerations
- Cloud tier sizing and performance
- Accelerator performance considerations
- Media configuration guidelines
- About dedicated versus shared backup environments
- Suggestions for NetBackup media pools
- Disk versus tape: performance considerations
- NetBackup media not available
- About the threshold for media errors
- Adjusting the media_error_threshold
- About tape I/O error handling
- About NetBackup media manager tape drive selection
- How to identify performance bottlenecks
- Best practices
- Best practices: NetBackup SAN Client
- Best practices: NetBackup AdvancedDisk
- Best practices: Disk pool configuration - setting concurrent jobs and maximum I/O streams
- Best practices: About disk staging and NetBackup performance
- Best practices: Supported tape drive technologies for NetBackup
- Best practices: NetBackup tape drive cleaning
- Best practices: NetBackup data recovery methods
- Best practices: Suggestions for disaster recovery planning
- Best practices: NetBackup naming conventions
- Best practices: NetBackup duplication
- Best practices: NetBackup deduplication
- Best practices: Universal shares
- NetBackup for VMware sizing and best practices
- Best practices: Storage lifecycle policies (SLPs)
- Best practices: NetBackup NAS-Data-Protection (D-NAS)
- Best practices: NetBackup for Nutanix AHV
- Best practices: NetBackup Sybase database
- Best practices: Avoiding media server resource bottlenecks with Oracle VLDB backups
- Best practices: Avoiding media server resource bottlenecks with MSDPLB+ prefix policy
- Best practices: Cloud deployment considerations
- Measuring Performance
- Measuring NetBackup performance: overview
- How to control system variables for consistent testing conditions
- Running a performance test without interference from other jobs
- About evaluating NetBackup performance
- Evaluating NetBackup performance through the Activity Monitor
- Evaluating NetBackup performance through the All Log Entries report
- Table of NetBackup All Log Entries report
- Evaluating system components
- About measuring performance independent of tape or disk output
- Measuring performance with bpbkar
- Bypassing disk performance with the SKIP_DISK_WRITES touch file
- Measuring performance with the GEN_DATA directive (Linux/UNIX)
- Monitoring Linux/UNIX CPU load
- Monitoring Linux/UNIX memory use
- Monitoring Linux/UNIX disk load
- Monitoring Linux/UNIX network traffic
- Monitoring Linux/Unix system resource usage with dstat
- About the Windows Performance Monitor
- Monitoring Windows CPU load
- Monitoring Windows memory use
- Monitoring Windows disk load
- Increasing disk performance
- Tuning the NetBackup data transfer path
- About the NetBackup data transfer path
- About tuning the data transfer path
- Tuning suggestions for the NetBackup data transfer path
- NetBackup client performance in the data transfer path
- NetBackup network performance in the data transfer path
- NetBackup server performance in the data transfer path
- About shared memory (number and size of data buffers)
- Default number of shared data buffers
- Default size of shared data buffers
- Amount of shared memory required by NetBackup
- How to change the number of shared data buffers
- Notes on number data buffers files
- How to change the size of shared data buffers
- Notes on size data buffer files
- Size values for shared data buffers
- Note on shared memory and NetBackup for NDMP
- Recommended shared memory settings
- Recommended number of data buffers for SAN Client and FT media server
- Testing changes made to shared memory
- About NetBackup wait and delay counters
- Changing parent and child delay values for NetBackup
- About the communication between NetBackup client and media server
- Processes used in NetBackup client-server communication
- Roles of processes during backup and restore
- Finding wait and delay counter values
- Note on log file creation
- About tunable parameters reported in the bptm log
- Example of using wait and delay counter values
- Issues uncovered by wait and delay counter values
- Estimating the effect of multiple copies on backup performance
- Effect of fragment size on NetBackup restores
- Other NetBackup restore performance issues
- About shared memory (number and size of data buffers)
- NetBackup storage device performance in the data transfer path
- Tuning other NetBackup components
- When to use multiplexing and multiple data streams
- Effects of multiplexing and multistreaming on backup and restore
- How to improve NetBackup resource allocation
- Encryption and NetBackup performance
- Compression and NetBackup performance
- How to enable NetBackup compression
- Effect of encryption plus compression on NetBackup performance
- Information on NetBackup Java performance improvements
- Information on NetBackup Vault
- Fast recovery with Bare Metal Restore
- How to improve performance when backing up many small files
- How to improve FlashBackup performance
- Veritas NetBackup OpsCenter
- Tuning disk I/O performance
Best practices: Disk pool configuration - setting concurrent jobs and maximum I/O streams
Setting Maximum Concurrent Jobs and Maximum I/O Streams are an important means of throttling workloads where both AdvancedDisk or an MSDP disk pool is the target.
The correlation between Maximum Concurrent Jobs set on the storage unit, and Maximum I/O Streams set on the disk pool is significant. The Maximum I/O Streams setting on the disk pool, whether MSDP or AdvancedDisk, sets the maximum number of streams that can run concurrently on that disk pool, regardless of the Maximum Concurrent Jobs setting on the storage unit, even if multiple storage units exist referencing the same disk pool.
In the case that there are multiple storage units that reference the same disk pool, the total number of concurrent jobs that is configured to run is equal to the total of the Maximum Concurrent Jobs that is set across each storage unit referencing that specific disk pool. Whatever that total Maximum Concurrent Jobs number is, the maximum jobs that can actually be run is a number that is less than or equal to the Maximum I/O Streams set on the disk pool.
For MSDP pools, it is recommended that the Maximum Concurrent Jobs sum should not be greater than 90% of the Maximum I/O Streams set on the disk pool, or by subtracting 10 from the total, whichever is greater.
For example, a single MSDP pool with Maximum I/O Streams set to 200 should have a total Maximum Concurrent Jobs value not greater than 180. If more than one storage unit references that MSDP pool, the sum across all those storage units should be 180 or less. Meaning that in this example, a single storage unit referencing that disk pool would have Maximum Concurrent Jobs set to 180. If there were two storage units that referenced that same MSDP pool, then that total Maximum Concurrent Jobs could be 100 set on one and 80 set to the other, or any combination totaling no more than 180.
In the case of AdvancedDisk disk pools, we recommend staying with the 90% recommendation, as that still reserves some streams for duplication.
For example, in the case of an AdvancedDisk pool with Maximum I/O Streams set to 30, the Maximum Concurrent Jobs should be set to no more than 27.
That said, to minimize complexity, we recommend that the use of multiple storage units referencing the same disk pool is limited, and ideally avoided.
The 10% of the Maximum I/O Streams that is reserved is specifically used for secondary operations, like the use of A.I.R. with MSDP, or duplication activities which are supported with both AdvancedDisk and MSDP.
One of the most common backup performance issues is caused by a mismatch between the Maximum I/O Streams and Maximum Concurrent Jobs. This configuration error often results in throughput bottlenecks that can prevent workloads from completing within their allotted backup windows.
When the Maximum I/O Streams is set on the disk pool, the default is set to 2 per volume. It is recommended that you set this value to 10 I/O streams per independent LUN. For example, if you have 6 LUNs per disk pool, set the value to 10 and the total Maximum I/O streams would be 60 (6 x 10). However, a disk pool created for MSDP works differently. The entire disk pool is considered to be one volume regardless of the number of LUNs included. Therefore, for a 6 LUN MSDP disk pool, the value should be set to 60. .
The recommended way to determine the ideal setting for Maximum I/O Streams is to start low (proportional to the number of volumes in the disk pool), monitor compute, I/O, and network bandwidth, and increase to the point that jobs are not waiting in queue for more than a minute before becoming active, and while ensuring that compute, I/O, and network bandwidth does not become depleted. Remember when the Maximum I/O Streams setting is changed on a disk pool, that Maximum Concurrent Jobs should be updated based upon the aforementioned guidance. Try to keep the aggregate media server hardware resource usage under 75%.
It is not recommended that Maximum I/O Streams ever be set to unlimited.
More information is available in the following technical article:
NetBackup - Configuring the Max Jobs and Max IO Streams settings