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Client Backup is Running Slower Than Expected


Possible causes for a single client’s backup to run slower than expected.


A single client’s backup is running slower than expected.
The speed of file-level, application-level and Bare Metal backups are running slower than expected.

For more detailed information on backup failures and performance issues see Unitrends KB 5062 - Backup Failures and Performance Issues


Typically, it best to use the following test procedures in order to find the bottleneck causing the slow backup speed.  Alternatively, backups can completed using multi-threaded jobs.  Multi-threaded jobs are particularly useful for large servers such as file servers.

  1. Temporarily disable any software anti-virus software.  Some anti-virus software’s need to be configured to NOT scan files on backup or when files are read.
  2. Verify that the client being protected and the backup appliance are both registering at full network speed on the switch which they are connected to.  The backup appliance’s NIC speed can be seen in the Network interface as well.
  3. Servers containing a large number of very small files can problematic when these files are presented for backup.  Unfortunately, the most effective resolution to this problem requires either an upgrade of the OS or an upgrade of the client’s hardware or both. You should also consider using aliases for servers with a large number of small files.  Also see Why use a client alias?
  4. As a backup is running, view the task manager or system performance monitor to see what hardware components are being taxed.  You may also verify that all raid arrays and hard drives on the client server are healthy.  Slow backups speeds may be an indication of a greater hardware problem.


The speed of backup is affected by many variables within the network, which may or may not include the following:

  1. Anti-virus software actively scanning files being backed up
  2. Available network bandwidth
  3. Client OS ability to seek and present files for backup
  4. Client hard ware limitations
If all backups are running slowly the problem may originate on the appliance itself.  Please suspend backup jobs, open a SSH connection to the appliance, and enter the following command:
screen -i
The above command (on version 10.1+) will run manual database maintenance, which will run for a default of 30 minutes (can be set up to 59 minutes, navigate in the web GUI to Configure > Appliances > (select your appliance) > Edit > Advanced > General Configuration > DBMaintMaxRuntime and set a value up to 59) once this operation is complete you can reactivate your schedules.  If you are still having issues check below.

If you are running a virtual appliance (UB) check to make sure that your appliance is deployed on storage that can operate at a recommended sustained write I/O of 500 IOPS, for large scale performance UBs protecting 20TB or more it is recommended to scale up IOPS, our largest hardware appliances have sustained database IOPS in excess of 2000.

Confirm that your switch port is hard set to gig full, or 10G where applicable.  It is common when using auto-negotiate settings on your switch for the connection to be downgraded in times of high network utilization, it is recommended for all high traffic servers to use fixed switch speeds.

If you did not find any issues with locked tables please navigate in the web GUI to Configure > Appliances > (select your appliance) > Edit > Advanced > Support Toolbox > Disk Status, if you see any failed drives, drives with "pending sectors" or alerts indicating the RAID is degraded, please contact support.

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