Error Message

No error messages are received. The VM based backup with SQL Application GRT selected takes longer compared to if the same SQL virtual machine is backed up in traditional fashion, i.e. Remote Agent based backup.

 

The filestream enabled SQL database may contain a large number of files. When it is backed up with the application GRT for SQL checkbox enabled (Enable GRT for Microsoft SQL (database-level only) on virtual machines), it will take longer to read these files due to the large numbers. The impact is only seen if the SQL database filestream folder has a large number of files.

Note: It is not recommended to de-select the SQL Application GRT checkbox when performing a virtual machine-based backup which has a SQL instance running on it.

Workaround:

Perform Remote agent based backup of the SQL server if performance drops are seen (for the scenario described in this technote) as it backed up faster compared to the VM based backup in the scenario described above.

Figure 1: VM-based selection



Figure 2: Remote Agent-based selection.

Note: There can be other factors that may impact the performance of an Remote agent-based job, but for the scenario this technical article is written had a SQL Virtual machine with one SQL database containing 150 GB of filestream data. The VM based backup took around 12 hours whereas the agent based backup completed in around 5 hours. The VM-based SQL virtual machine backup spent the majority of time in reading the large amount of filestream data which resided on disk.

At this time, there are no plans to address this issue through a patch or hotfix in the current or previous versions of the software. Although this issue may potentially be resolved in a future major revision, it is not currently scheduled for any upcoming release. If this issue has a significant business impact on your continued use of the product, please contact your Sales representative or the Sales team to discuss your concerns.