Exchange Logs and the VSS guest helper

[odge]

Hi

While this isn't necessarily a bug, I thought I'd point out my experience with the performance of the VeeamGuestHelper when the guest helper must iterate throgh the Exchange log files that will need to be truncated at the end of the backup.
This is shown as the "preparing Guest for Hot Backup" step before a snapshot is taken.

Number of files in the Directory Vs Time to spent "preparing"
+-40000 files = +-8 minutes
+-85000 files = +- 14 minutes
+- 220000 files = +-58 minutes

below 100'000 files the time seems relatively linear per log file, with a slight increase in speed (decrease in time) per file as you increase the number of files. But at a certain point, it becomes really slower. If we had to apply rule of thumb for below 100'000 files, on 220'000, we'd get a time of between 44 minutes (based on and 40k files) and 36 minutes (based on 85k files). We've done various backups in the last few days during an exchange migration, and found this slowdown at certain number of files quite interesting, possibly related to to the list type you are using when enumerating through the files? Or an issue with VSS itself?

Kind Regards

[Vitaliy S.]

Hi Matthew,

Thanks for sharing the results of your testing, I will definitely share it with our QA for further look.

Thanks!