Amanda Parallel Backups

Improving Amanda performance when backing up multiple clients

You have successfully installed Amanda, and your backups are running to completion. Everything seems good, and you have even tested your recovery procedure. However, your “back-of-the-envelope” calculations show that your backups seem to be taking too much time. While there can be many causes, perhaps the problem is that your client backups are being run sequentially instead of in parallel.

This illustration shows the potential benefit of running the backups in parallel – the total time for the backup can be less in a parallel backup.

amanda parallel chart

Amanda uses several parameters and settings to determine the number of parallel backups. In order to run parallel backups all of these settings must work in concert (getting even one of them incorrect can cause Amanda to run your backups sequentially):

  • The amount of space available on the holding disk(s).
  • The amount of estimated network bandwidth that will be consumed by each backup.
  • The Parallel Backups setting in Zmanda Management Console (ZMC), which is the inparallel setting in the amanda.conf file. This parameter limits the total number of parallel backups dispatched by the Amanda server.
  • The Parallel Backups (clients) setting in Zmanda Management Console, which is the maxdumps setting for a given dumptype. This parameter limits the number of parallel backups dispatched for a single client


To download the complete white paper, which discusses these settings in detail, and to have access to other valuable Amanda resources just register, free of charge, to the Zmanda Network.

Cycorp has been using Amanda for over 7 years now. In that time, we have scaled from backing up a few Gigs to a DLT 2000XT drive to over 2 Terabytes with an SDLT600-based autoloader. Amanda has always scaled with us, and I have no doubt it always will..."


Charles Smith
Cycorp Inc., Austin, TX.
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