Prakasma Venkatachalam
Why initial version of S3 object’s Version ID is "null" always?
2 Answers
Otavio Gallego
If I were to guess, I’d say it is because versioning was disabled when the object was first uploaded.
David Bower
Otavio is correct.
A Version ID is only generated if versioning is turned on at the point in time when the object is uploaded.
Since Version ID is available for all objects once versioning is turned on, some value has to be used as the Version ID for objects uploaded before versioning was turned on. This value is null.
Hence, all objects that were in a bucket before versioning was turned on are signified by their Version ID being null.
See https://docs.aws.amazon.com/AmazonS3/latest/userguide/Versioning.html
I don’t know the answer but it could be some kind of marker to highlight the initial version of an object.