Nextcloud, mariadb install error

Troubleshooting
1

When I try to install nextcloud from the diepi-launcher menu I get the following error

dpkg: error processing package mariadb-server-10.1 (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of mariadb-server:
 mariadb-server depends on mariadb-server-10.1 (> = 10.1.23-9 + deb9u1); however:
  Package mariadb-server-10.1 is not configured yet.

dpkg: error processing package mariadb-server (--configure):
 dependency problems - leaving unconfigured
Processing triggers for systemd (232-25 + deb9u2) ...
Errors were encountered while processing:
 mariadb-server-10.1
 mariadb-server
E: Sub-process / usr / bin / dpkg returned an error code (1)

[FAILED] DietPi-Software | G_AGI: mariadb-server
[INFO] DietPi-Software | If problems persist, please report this to DietPi for investigation


-------------------------------------------------- ------------------
- DietPi has encounted an error, and, is unable to continue -
- Please create a ticket: https://github.com/Fourdee/DietPi/issues -
- Copy and paste the BLUE lines below, into the ticket -
-------------------------------------------------- ------------------


#### Details:
- Date | Mon 2 Jul 02:13:09 CEST 2018
- BR sent? | 0: 0119d338-f799-408b-bb37-0cd451714ff5
- DietPi version | v6.9
- Img creator | n / a
- Pre-image | n / a
- SBC device | RPi 3 Model B (armv7l) (index = 3)
- Distro | stretch (index = 4)
- Command | G_AGI: mariadb-server
- Exit code | 100
- Software title | DietPi-Software

#### Expected behavior:
<! - What SHOULD be happening? ->

#### Actual behavior:
<! - What IS happening? ->

#### Steps to play:
<! - Explain how to reproduce the issue ->

#### Additional Information:
<! - if applicable ->

#### Additional logs:
`` `
Log file contents:
Preconfiguring packages ...
Selecting previously unselected package mariadb-common.
(Reading database ... 28918 files and directories currently installed.)
Preparing to unpack ... / mariadb-common_10.1.23-9 + deb9u1_all.deb ...
Unpacking mariadb-common (10.1.23-9 + deb9u1) ...
Selecting previously unselected package mariadb-client-core-10.1.
Preparing to unpack ... / mariadb-client-core-10.1_10.1.23-9 + deb9u1_armhf.deb ...
Unpacking mariadb-client-core-10.1 (10.1.23-9 + deb9u1) ...
Selecting previously unselected package mariadb-client-10.1.
Preparing to unpack ... / mariadb-client-10.1_10.1.23-9 + deb9u1_armhf.deb ...
Unpacking mariadb-client-10.1 (10.1.23-9 + deb9u1) ...
Selecting previously unselected package mariadb-server-core-10.1.
Preparing to unpack ... / mariadb-server-core-10.1_10.1.23-9 + deb9u1_armhf.deb ...
dietpi @ raspberry: ~ $

I have uninstalled all traces of mariadb and manually deleting all traces of mysql does not solve anything

Thank you

2

Was this a totally fresh installation of Nextcloud and MariaDB?

We have now already 3 reports about this issue, but were not able to replicate on several tests we did and could not find the issue.

Could you check your error logs:
systemctl status mysql
journalctl
for errors related to mysql, like e.g. this:

Jun 14 21:43:49 DietPi mysqld[13213]: 2018-06-14 21:43:49 1988263936 [Note] /usr/sbin/mysqld (mysqld 10.1.23-MariaDB-9+deb9u1) starting as process 13213 ...
Jun 14 21:43:49 DietPi mysqld[13213]: 2018-06-14 21:43:49 1988263936 [Warning] Can't create test file /var/lib/mysql/DietPi.lower-test
Jun 14 21:43:49 DietPi mysqld[13213]: #007/usr/sbin/mysqld: Can't change dir to '/var/lib/mysql/' (Errcode: 13 "Permission denied")
Jun 14 21:43:49 DietPi mysqld[13213]: 2018-06-14 21:43:49 1988263936 [ERROR] Aborting

Our only idea so far was, that if you placed your dietpi_userdata directory onto an external drive, that does not have an own power supply (e.g. 2,5" drive powered via USB), might just loose power, if the RPi is under heavy load (dietpi-software installation running). Might this be your case as well? For external USB drive you should have a strong stable power supply for your RPi and enable max USB power within dietpi-software configuration.

If you have a GitHub account, please let’s go on discussion here: https://github.com/Fourdee/DietPi/issues/1850
I will reopen the issue, after your comment.