I am in the process of using the Data Migration Assistant to move a local DB to Aszure SQL. The schema transfer went well, and 243 of the 246 tables all were able to transfer their data with no errors.

However, the transfer has been running for 13+ hours, and over the last three hours, three of the tables have not budged on their percent complete. One is at 92.3%, one is at 93.9%, and the last is at 98.5%.

Some questions:

  • At this point, can I safely assume that this is a failed transfer, at least of these three tables?
  • I don't see a "stop" button. If I wanted to, how would I abort this process?
  • If I were to abort the process, is there some way to manually finish the transfer of data from just these three tables?
  • Depending on the size of table, you can use visual studio data compare and sync the difference only. Dec 6, 2017 at 14:51
  • Thanks @SqlWorldWide! When you say, "Depending on the size of table", what is the threshold at which point it's not worth trying? Dec 6, 2017 at 14:54
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    Really do not know. Sorry I do not have a number in mind. Try one first if you abort the current sync. I am thinking you are over 95% synced, so you can avoid full sync. Of course compare have to do full scan. Dec 6, 2017 at 14:56
  • Hello Casey. I shared your thread on an internal mailing list at Microsoft, and one of the Microsoft engineers interested in your thread would like to examine DMA logs located at <system drive>\Users\gennadyk\AppData\Local\DataMigrationAssistant. Could you possible put the content of that folder on your Public folder on OneDrive and share the URL with us. My e-mail is alberto_morillo @ Hotmail, if needed. Dec 6, 2017 at 19:53
  • Will do!! I'll email you a zip file with all of the logs. I've done a lot since I posted this. I went back and did the three tables individually. One of them had 40 million plus records. I whittled that down to ~3 million in the source db and did it again.. Just saying, they will have a lot of logs to dig though. Dec 6, 2017 at 20:07

1 Answer 1


A Microsoft Engineer examined the logs you shared with us and found the following error:

Dma.exe Information: 0 : 'Exception type: System.IO.IOException Message: There is not enough space on the disk.

It seems like the workstation that DMA is running on doesn’t have enough disk space to do schema extract.

The following is the explanation the Microsoft engineer shared with us about why DMA requires disk space:

The Extract service connects to a database, reads all of its objects and their properties, and then creates an in-memory model of the database. Similar to how the Build service validates the defined objects, the Extract service also checks for consistency and containment. The validation done here will also result in failures if you have a view that refers to a non-existent table same as with T-SQL! Additionally, unsupported or uncontained objects are blocked because these objects are not yet allowed in SQL Azure or the DAC in-memory model. Finally, once the in-memory model is complete and validated, a DACPAC is written to disk. Looking at the stack it’s a well-known Windows exception on not enough disk space.

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