tar: file changed as we read it

Question

I am using make and tar to backup. When executing makefile, tar command shows file changed as we read it. In this case,

Answer 1

I am not sure does it suit you but I noticed that tar does not fail on changed/deleted files in pipe mode. See what I mean.

Test script:

#!/usr/bin/env bash
set -ex
tar cpf - ./files | aws s3 cp - s3://my-bucket/files.tar
echo $?

Deleting random files manually...

Output:

+ aws s3 cp - s3://my-bucket/files.tar
+ tar cpf - ./files
tar: ./files/default_images: File removed before we read it
tar: ./files: file changed as we read it
+ echo 0
0

Answer 2

It worked for me by adding a simple sleep timeout of 20 sec. This might happen if your source directory is still writing. Hence put a sleep so that the backup would finish and then tar should work fine. This also helped me in getting the right exit status.

sleep 20
tar -czf ${DB}.${DATE}.tgz ./${DB}.${DATE}