# Migration from owncloud

When migrating from an existing owncloud install it's possible to use the same database,
or to rename the database to reduce confusion.

Before carrying out the migration it is important to prevent anyone from changing things.

Of course it's advised to carry out a backup of the database and files before any migration.

### Prevent people using owncloud
sudo -u apache php /usr/share/owncloud/occ maintenance:mode --on

### Migration whilst keeping owncloud data intact

This is the safest option as it is nondestructive to owncloud, but it will require
double the data storage during the migration.

#### Copy data over from one location to the other
The data layout is identical, it's just the location that differs.
```
rsync -aPh /var/lib/owncloud/ /var/lib/nextcloud/
```

## Renaming the database
This is optional but might serve to confuse less, and prevents any changes to the owncloud
database in case there are issues requiring a fallback. Naturally use better credentials and
use the correct database names for your setup!

##### MySQL
```
mysql -e 'create database nextclouddb;'
mysql -e "grant all on nextclouddb.* to 'nextcloud_user'@'localhost' identified by 'nextcloud_pass';"
mysqldump -v ownclouddb | mysql  -D nextclouddb
```

##### PostgreSQL
```
sudo -u postgres psql <<EOF
 /* Create the user for nextcloud */
 CREATE USER nextcloud_user WITH PASSWORD 'nextcloud_pass';

 /* KILL ALL EXISTING CONNECTION FROM ORIGINAL DB (ownclouddb)*/
 SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity
 WHERE pg_stat_activity.datname = 'ownclouddb' AND pid <> pg_backend_pid();

 /* CLONE DATABASE TO NEW ONE(nextclouddb) */
 CREATE DATABASE nextclouddb WITH TEMPLATE ownclouddb OWNER nextcloud_user;

 GRANT ALL PRIVILEGES ON DATABASE nextclouddb TO nextcloud_user;

/* The tables need to be transferred in owner as well */
\c nextclouddb;
REASSIGN OWNED BY owncloud_user TO nextcloud_user;
 EOF

```
Don't forget to update pg_hba.conf to allow access to the new database as the new user!

```
host nextclouddb nextcloud_user ::1/128 password
host nextclouddb nextcloud_user 127.0.0.1/32 password
```

### Migration in place without preserving owncloud data

If there is not sufficient disk then data can be moved, this will break owncloud in the process
and there won't be a fallback option if things go wrong beyond restiring data/backups.

#### Copy data over from one location to the other
```
mv /var/lib/owncloud/* /var/lib/nextcloud/
```

#### Renaming the database
This is even more optional since the old database will be destroyed in the process, but it may serve
to lessen confusion later on for future maintenance. Again replace with the desired credentials and
database names for your environment.

Note that since the database sizes are small it's more reliable and safer for the data stores to follow
the steps to duplicate the database laid out above.

##### MySQL
```
mysql -e 'create database nextclouddb;'
mysql -e "grant all on nextclouddb.* to 'nextcloud_user'@'localhost' identified by 'nextcloud_pass';"
mysql ownclouddb -sNe 'show tables' | while read table;  do mysql  -sNe "rename table ownclouddb.$table to nextclouddb.$table;"; done
```

##### PostgreSQL
```
sudo -u postgres psql <<EOF
 /* Create the user for nextcloud */
 CREATE USER nextcloud_user WITH PASSWORD 'nextcloud_pass';

 /* KILL ALL EXISTING CONNECTION FROM ORIGINAL DB (ownclouddb)*/
 SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity
 WHERE pg_stat_activity.datname = 'ownclouddb' AND pid <> pg_backend_pid();

 /* ALTER DATABASE to rename it */
 ALTER DATABASE ownclouddb RENAME TO nextclouddb;
 ALTER DATABASE nextclouddb OWNER TO nextcloud_user;

 GRANT ALL PRIVILEGES ON DATABASE nextclouddb TO nextcloud_user;

/* The tables need to be transferred in owner as well */
\c nextclouddb;
REASSIGN OWNED BY owncloud_user TO nextcloud_user;
EOF
```

Again remember to update pg_hba.conf so the new database and user can be used.

### Bring over the old configuration and update paths
The config can be copied as-is which will preserve most settings. This is a coarse rename of everything
from owncloud to nextcloud, but if the database isn't renamed then this too much. Verify the database
credentials and name in the config file are correct before moving on to the next step.
```
cp /etc/owncloud/config.php /etc/nextcloud/config.php
sed -i 's/owncloud/nextcloud/g' /etc/nextcloud/config.php
```

### Enable the nextcloud interface on httpd
If using httpd then enable the interface the same way as the README describes for a fresh install
```
ln -s /etc/httpd/conf.d/nextcloud-access.conf.avail /etc/httpd/conf.d/z-nextcloud-access.conf
```

### Carry out any migration required
A migration step for database schemas etc needs to be carried out to ensure everything is correct.

Although the WebUI will be prompting the standard "click here to update" it is best for this major
migration to carry it out at the command line.
```
sudo -u apache php /usr/share/nextcloud/occ upgrade
```

### Verify that everything looks right
It's best at this stage to enter as an admin and have the instance in single user mode only
```
sudo -u apache php /usr/share/nextcloud/occ maintenance:singleuser --on
sudo -u apache php /usr/share/nextcloud/occ maintenance:mode --off
```
__NOTE__ It is usual for things like webdav to be disabled during singleuser which may prevent seeing
files, however just use this to verify the admin screens. On testing apps needed to be disabled
and then enabled again for nextcloud to correctly pick them up.

### Enable allow people to use nextcloud
If things are looking good then open the floodgates to everyone else.
```
sudo -u apache php /usr/share/nextcloud/occ maintenance:singleuser --off
```

### Clean up the owncloud stuff
Finally clean up the old owncloud install, replace with the database and user for your own setup.
```
dnf remove -y owncloud\*
rm -rf /var/lib/owncloud /etc/owncloud /etc/httpd/conf.d/*owncloud*
# mysql
mysql -e "drop database ownclouddb; drop user owncloud_user@'localhost';"
# postgres
sudo -u postgres psql <<EOF
DROP DATABASE ownclouddb;
DROP USER owncloud_user;
EOF
```