Replibit - Agent Simple Disk I/O Throttling

Disk I/O Throttling

This feature is present in Replibit Agent 2.23 and newer.
Replibit Agent 2.23 will begin staggered release in May 2019.

The Replibit agent now includes a simple mechanism for limiting storage disk I/O throughput in order to prevent the agent from adversely affecting performance of the protected system.

This feature can be especially useful when backing up a protected system using low-end storage or running within heavily populated virtual infrastructure. 

Disk I/O Throttling Settings

Disk throttling can be enabled by modifying the agent configuration file on the protected system.

If your protected system performance is being adversely affected by backups, try setting these flags in aristos.cfg.  Adjust throttling values to find a happy medium between backup time and user experience.

Two new feature control flags are configurable within the aristos.cfg configuration file:

• MAX_READ_MB_PER_VOLUME: Set the maximum disk read speed (per volume) in MB/sec for incremental backups.  The default value is 0 (zero) meaning unlimited.
• (5-10MB/sec is a reasonable setting for this value in most cases.)
• MAX_READ_MB_PER_VOLUME_FOR_FULL: Set the maximum disk read speed (per volume) in MB/sec for full backups.  The default value is 0 (Zero) meaning unlimited.
• (25-25MB/sec is a reasonable setting for this value in most cases.)

It is recommended to set MAX_READ_MB_PER_VOLUME_FOR_FULL to a value high enough to ensure full backups complete in a reasonable timeframe.  (e.g. 25-35MB/sec or more depending on volume size)

To determine the baseline performance for a given protected system, open Resource Monitor and observe the active disk activity during an incremental backup.  Limit the disk I/O to no more than 50-75% of the average transfer speed observed without throttling enabled to ensure that your users are not impacted by agent disk activity.

Note:  The value for both features must be an integer.  (For example:  5, not 5.5)