Slow: Move file server data to azure server


Came across an issue of slow data copy from on premise to Azure VM and wondering if anyone else had the same issue.

Internet speed on premise is 100 Mbps Down/Up. Tried copying 120 GB of data for 10 hours and it only copied around 28 GB. Used the Robocopy with command:

Anything else could have been done or any other ideas to best/fast way to copy to the Azure VM from on premise that anyone can suggest of?

Data transfer speeds will depend on the type of data you are copying.
If your 120GB has many small files, the upload will take a long time because of the overhead and the way file transmission of small files works.

Azure won’t be to blame.

You say you want to copy a VM, is this just for backup purposes or it needs to run in Azure. If the latter is true, you should use site replication to Azure and then switch off replication when it has failed over to Azure.

We could do with more info from you though.


Hey there!
Here you can find more information, I hope it helps

Hi @NaveenD,

A long ago I had to move around 2TB of data to azure storage for one of my client but the client had only small files like ppt, dwg, word, pdf etc., When I started to upload the files I get the estimation time as morethan1 week. I saw the file size is effecting the upload performance. This very much annoyed me So, I started to do a research and I learned something as below:

Remember when you copy files anywhere onsite or offsite network, if the files in smaller chunks it will definitely take longer time depends to the file size no matter how much upload/download speed you have.

At the same time when you copy large size files like 10 GB or 20 GB (.iso, zip, rar) you will get the maximum of available upload/download speed by your network.

Since you have not mentioned how much of data you are moving to azure so for example I assume 2TB as in my case.

  • I assume you are using windows server So, use windows server backup services to backup the partition.
  • Move the files using Azure Storage Explorer or AzCopy (I prefer Azure Storage Explorer as it has GUI option)
  • Attach the disk in any azure VM and recover the files from backup

This way I was able uploaded 2TB of my files within 2days with an average upload speed of 80mbps in 100mpbs.

Note: If you have multiple partitions create separate backup file for each partition by partition level.

I hope this will be useful.



Hi @tjnihal,

Thanks for the wonderful Idea. I followed your advice, after using the backup .vhd file I was able to upload the file very quickly.
Thanks again.


It was a pleasure helping you. :grinning: