Absolutely - got my script working to create the backup - it uses a SAMBA/CIFS Share as target-dir. It’s mounted this way in the fstab:
//idonttellyou.your-storagebox.de/idonttellyou /mnt/backup cifs iocharset=utf8,rw,credentials=/etc/backup-credentials.txt,uid=backupuser,gid=backupuser,file_mode=0660,dir_mode=0770,vers=3.1.1 0 0
But when trying to prepare the backup the following error occurs:
2025-04-01T09:57:04.089902-00:00 0 [ERROR] [MY-012574] [InnoDB] Unable to lock ./#innodb_redo/#ib_redo0 error: 13
2025-04-01T09:57:04.089977-00:00 0 [Note] [MY-012575] [InnoDB] Check that you do not already have another mysqld process using the same InnoDB data or log files.
2025-04-01T09:57:04.090020-00:00 0 [Note] [MY-012894] [InnoDB] Unable to open './#innodb_redo/#ib_redo0' (error: 11).
2025-04-01T09:57:04.090066-00:00 0 [ERROR] [MY-012930] [InnoDB] Plugin initialization aborted with error Cannot open a file.
2025-04-01T09:57:04.168315-00:00 0 [ERROR] [MY-011825] [Xtrabackup] innodb_init(): Error occured
which leads me to this article:
Which leads to:
We will have to investigate if there is anything we can do here, for now, please prepare the backup on your local filesystem
Am I just missing a mount option or is the aforementioned case with the double renaming still the case?
Would love to do the prepare within the SAMBA/CIFS Share, cause otherwise we would need to mount another SSD Volume with a large amount of Space just to have a temp dir to create and prepare the backup, cause the local filesystem is very tiny (for example /var/lib/mysql is also just another SSD volume mounted)
//Edit
Versions are:
percona-release/unknown,now 1.0-29.generic all [installed,upgradable to: 1.0-30.generic]
percona-telemetry-agent/stable,now 1.0.2-2.bookworm amd64 [installed,upgradable to: 1.0.3-4.bookworm]
percona-xtrabackup-80/unknown,now 8.0.35-32-1.bookworm amd64 [installed]
percona-xtradb-cluster-client/now 1:8.0.37-29-1.bookworm amd64 [installed,local]
percona-xtradb-cluster-common/now 1:8.0.37-29-1.bookworm amd64 [installed,local]
percona-xtradb-cluster-server/now 1:8.0.37-29-1.bookworm amd64 [installed,local]
percona-xtradb-cluster/now 1:8.0.37-29-1.bookworm amd64 [installed,local]
To create and prepare the backup, i’m having a backup script running from a remote server which checks which node he will use (checking that it’s in Synced state). Actually we dont have a read only node, thats why the backup and prepare happens on a read/write node.
Here are the commands from my script which run:
backup:
ssh $SSH_OPTIONS "$SSH_USER@$backup_node" "
mkdir -p $BACKUP_PATH &&
xtrabackup --defaults-extra-file=$MYSQL_CREDENTIALS --backup --target-dir=$BACKUP_PATH
" > >(tee -a /tmp/backup_$backup_node.log) 2>&1
prepare:
ssh $SSH_OPTIONS "$SSH_USER@$backup_node" "
mkdir -p $BACKUP_PATH &&
xtrabackup --defaults-extra-file=$MYSQL_CREDENTIALS --prepare --target-dir=$BACKUP_PATH
" > >(tee -a /tmp/backup_$backup_node.log) 2>&1
the SSH_USER we are using here is a simple user which we created as follows:
useradd -d "/home/backupuser" -m -s /bin/bash -p 'IDONTTELLYOU' backupuser
usermod -aG mysql backupuser
The mysql backup_user we use got created as follows:
CREATE USER 'backup_user'@'%' IDENTIFIED BY 'IDONTTELLYOU';
GRANT RELOAD, PROCESS, LOCK TABLES, REPLICATION CLIENT ON *.* TO 'backup_user'@'%';
GRANT SELECT ON performance_schema.global_status TO 'backup_user'@'%';
GRANT SELECT ON performance_schema.replication_group_members TO 'backup_user'@'%';
GRANT SELECT ON performance_schema.keyring_component_status TO 'backup_user'@'%';
GRANT SELECT ON performance_schema.log_status TO 'backup_user'@'%';
GRANT BACKUP_ADMIN ON *.* TO 'backup_user'@'%';
FLUSH PRIVILEGES;