Storage Migration Service Inventory completed with errors

Copper Contributor

Hi, I am running Windows Server 2019 Storage Migration Service Server to migrate a Windows Server 2012 R2 Server to Windows Server 2019. The Job, on 3 of my most important shares, says Completed with Errors"and due to the nature of the information I cannot ignore this and need to identify which folder have issues and errors. I cannot seem to find much in the Windows log files, any advise will be appreciated. Thank you.

16 Replies

Hi. In the Transfer Details section for each server (a pull up from the bottom of the WAC screen), there is an option to save the Error log (as CSV) then open in Excel and look at the per-file errors. The codes will all be Windows Error codes as documented here:


If still not able to determine why certain files aren't transfering, let me know (I reserve the right to send you to MS Support for specific troubleshooting, naturally :grinning_face:).


Ned Pyle | Principal Program Manager, MS | @nerdpyle on twitter

@Ned Pyle Happy to report back that I have found the directories\files that caused the issue. Another issue, after identifying the issue, correct it and the start the transfer again, it runs through every directory\file again (4TB) and it runs for 25+ hours ... Any idea? Thank you

@Kobus_Olivier It's going to examine every file, antually, but it should not be transferring them all again - you will see the difference in the transfer details page and the saved CSV. We are working on some improvements in delta transfer perf, but most customers see reduced time between transfers if there aren't many changes. How many Cores do you have on the Orchestrator and Destination computer? 

Hi, ok I understand. Both the server have dual core CPU’s with 8 GB RAM - what I am seeing now on the destination is that Windows Defender is hammering the CPU average of 60%. Is there any exclusions for Storage Migration Service? Thank you, Regard Kobus

@Kobus_Olivier Re: defender... ouch. They have always told us to expect no more than 5-10% increased utilization. As atest, if you exclude folders where SMS is writing to (or temporarily disable real-time protection), do you see the performance improve?  

@Ned PyleYes, I have disabled real time scanning and even seen and improvement. Still experiencing issues with about 22k files that have very explicit permissions (confidential data) where we cannot just go and alter these ..… Thank you for your help - appreciated.

@Ned Pyle 


Hi, I'm trying to troubleshoot the "couldn't inventory some devices" during the "scan" phase of the storage migration.


I realize that it may be choking on long file names and 0kb files but how do you access this CSV?


I don't see it anywhere in the WaC console.



@Thom Edwards Hi. There is no CSV for Inventory, only for Transfer. If you are seeing an inventory failure the details are in the SMS event logs. 

I found some bunk rights but what to do about the insanely long path names? I tried the registry key on the WAC server but the shares still fail to inventory for this reason.

Thanks so much.
SMS supports long path names, as long as NTFS allows, you don't need to make registry changes. If it's failing there you need to open a support case, that's not supposed to be happening.


@Ned Pyle 


Well I'm about to throw in the towel.  I started this huge 4TB 2008 R2 file server migration project about four weeks ago and I'm no further ahead.


  • inventory scan fails on some files with vague error messages - checked rights and enabled log path names
  • data transfer scan keeps getting stuck - doesn't timeout - spinning bagel for hours & hours - today it's stuck @ 44%
  • hesitant to STOP the transfer as last time I did that it auto created a bunch of preexistingdata folders which ended up filling the destination volumes and the data transfer failing due to lack of space - i ended up restarting the entire process only to be stuck AGAIN


There is just no rhyme or reason why it keeps struggling.  It worked great on my tiny test server so perhaps this server is just too big not to fail.


Not sure where to go from here.

HI. We've handled much bigger. I really recommend you not try to bang your head here further, open an MS support case. If we find a bug it's a free case, if it's something we can get working we will. Those support folks have access to me through an internal DL as well, you won't be hung out to dry.
thanks sir, will do
A related question. We're seeing five file failures out of nearly 4million files. The SMS proxy log appears to have one record for each file inventoried. Does it also enter a record for the failed files? I'm wondering what the syntax is for failed files, that would be useful to know in sorting through so many records. Success records say:
12/21/2022-10:04:20.683 [Verb] Endpoint scan on endpoint ShareName found file
I have the same issue, was able to find errors in the proxy logs for failed FOLDERS and corrected all those. Unfortunately I have 2 failed FILES now and can't find any errors in the SMS Logs for those.
I found that continuing on to transfer the files will give you good information for troubleshooting issues. You can run the transfer / sync multiple times.