Data Domain: ProtectPoint Backups Seem to Run Slowly

Summary: This article describes the concept surrounding ProtectPoint backup performance on Data Domain (DD).

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.
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Symptoms

  • ProtectPoint backups run slowly.
  • Users experience and report slow ProtectPoint backups.
  • ProtectPoint Increment-level backups take about the same time as Full-level backups.

 

Cause

In ProtectPoint environments, data is copied (static image saving) from Logical Unit Numbers (LUNs) on VMAX to DD vDisks. This process may appear to be a bottleneck. Metadata takes approximately five seconds per datafile to store index information.

 

Resolution

ProtectPoint backs up the whole LUN behind the scenes, no matter which datafile you are backing up. It also only moves the changed blocks from VMAX to DD. The first static image usually takes the longest to back up. Subsequent backups should take less time to complete.

ProtectPoint backup performance depends on the following:

  • LUN size
  • Number of LUNs
  • Data change rate
  • DD model and the number of shelves

For example:

  • 1 x 200GB size LUN
  • Change Rate of less than 1 % (no change between two subsequent backups)
  • VMAX destaging ("pb_save()" to be completed) that takes four minutes

This is roughly 880 MB/s, which is an expected rate of destaging.

 

Affected Products

Data Domain

Products

Data Domain, DD4500 Appliance
Article Properties
Article Number: 000060344
Article Type: Solution
Last Modified: 27 صفر 1448
Version:  5
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