Forum Discussion

jwithamwellcome's avatar
jwithamwellcome
Level 3
4 years ago

Restore Operation

Hello, I am attempting to restore several very large backup jobs and are encountering very slow response times which I can summarise into two categories:   1. "Assembling file list"  - This is pre...
8.3.x
Windows Server 2016
Nicolai's avatar
Nicolai
Moderator
4 years ago

Hi jwithamwellcome 

This is more general restore advice.

Restoring e.g 1 TB of small files will take much longer than restoring e.g 1 TB of Exchange data files. 

This is due to the overhead of creating files in the operating system.

So what to do :

  • Make sure antivirus doesn't scan the restored files
  • Restore in multiple datastreams (for disk based backups). Instead of restoring e.g 1 TB in one job, do a partial restore where the restore is split in e.g 4-6 streams. I assume this will help on the "Assembling file list" waiting time.
  • Memory - make sure client has enough memory, giant file list may consume all available memory causing paging.
  • Accept - you can't bet the law of physics :) 

Here is graph I did some years ago, who show restore speed and file size. Your mileage may vary, but it do show there is link between the two.

X axis - file size

Y axis - number of files

Hope this helps

Best Regards
Nicolai

  • jwithamwellcome's avatar
    jwithamwellcome
    Level 3
    4 years ago

    Many thanks for taking the time to explain Nicolai!

     

    I agree a single VMDK file will be faster than 4.5million 10KB .XML files  :) 

    Lots of memory in the client and Netbackup master server, but never exceeds 9GB of 100GB RAM.

     

    The project I am involved in is to restore ALL netbackup data to be ingested into our new backup product, our method is restore to a scratch location and it's then picked up by the other new backup app. The restores are slow hence my inquiry.  

    Are there any typical configuration tweaks I could make that would also help?

     

    Many thanks