filesystem permissions

MySQL & MariaDB Percona XtraBackup
1

I have a couple questions regarding filesystem permissions for the user running innobackupex/xtrabackup. I see the manual states:

“Once connected to the server, in order to perform a backup you will need READ, WRITE and EXECUTE permissions at a filesystem level in the server’s datadir.”

  1. What is the recommended user to run innobackupex/xtrabackup via a cronjob? Is it recommended to run it under root or under a non-privileged user that has read-only access to the datadir? I prefer to run backup jobs under a non-root account if possible, but wanted to make sure it won’t cause any issues. The files in my datadir are owned by mysql:mysql and are chmod 600 or 660, so I would have to alter that to allow a non-root user to access them. Just curious how others set this up.

  2. Does the user need write and execute privileges to the datadir or can it be read-only? In other words, does a backup write anything to the datadir?

Thanks for your help.

Ryan

2

It used to be (although I’m not sure that it still is this way) that even though xtrabackup only reads from the files, it opens them in read-write mode because that’s done via InnoDB, which as a database naturally needs to write the files.

If that is the case, you could consider running the tool as the mysql user.