Cannot open backup device '/var/opt/mssql/backup/MyDB.bak'. Operating system error 5(Access is denied.)

Question

I found a lot of cases, where people try to open a file from outside the docker container. But mine is clearly inside.

The whole message I am getting is:

$ /opt/mssql-tools/bin/sqlcmd -S localhost -U SA -P "mypw" -Q 
"RESTORE FILELISTONLY FROM DISK = '/var/opt/mssql/backup/MyDB.bak'"
Msg 3201, Level 16, State 2, Server 1c7bf85afdaf, Line 1
Cannot open backup device '/var/opt/mssql/backup/MyDB.bak'. Operating system error 5(Access is denied.).
Msg 3013, Level 16, State 1, Server 1c7bf85afdaf, Line 1
RESTORE FILELIST is terminating abnormally.

Same happens when I try to actually restore the database. Any idea what is going wrong?

I have the feeling it might be some permission things where need to change permissions for the file

$ ls -la var/opt/mssql/backup/MyDB.bak
-rw-r----- 1 501 dialout 3395584 Jan 16 02:12 var/opt/mssql/backup/MyDB.bak

Answer 1

The solution was to change the permission of the file. I needed to do:

docker exec -it -u root MicrosoftSQLServer "bash"

Then change the user (whoami returns mssql when I run the docker container not as root)

chown mssql /var/opt/mssql/backup/TestDB.bak

And then it works.