My Raspberry Pi has a 128GB SD Card with Arch ARM and
- Apache
- NextCloud
installed on it and it seemingly non-stop interfaces with the SD Card. With iotop I found out that mysqld is seemingly the process that writes most data to the disk. In the mysql shell I then found the following:
show processlist;
+------+--------------+-----------+-----------+---------+------+--------------------------+------------------+----------+
| Id | User | Host | db | Command | Time | State | Info | Progress |
+------+--------------+-----------+-----------+---------+------+--------------------------+------------------+----------+
| 1 | system user | | NULL | Daemon | NULL | InnoDB purge coordinator | NULL | 0.000 |
| 2 | system user | | NULL | Daemon | NULL | InnoDB purge worker | NULL | 0.000 |
| 3 | system user | | NULL | Daemon | NULL | InnoDB purge worker | NULL | 0.000 |
| 4 | system user | | NULL | Daemon | NULL | InnoDB purge worker | NULL | 0.000 |
| 5 | system user | | NULL | Daemon | NULL | InnoDB shutdown handler | NULL | 0.000 |
| 1846 | root | localhost | NULL | Query | 0 | Init | show processlist | 0.000 |
| 1852 | oc_stdcerr13 | localhost | nextcloud | Sleep | 0 | | NULL | 0.000 |
| 1853 | oc_stdcerr13 | localhost | nextcloud | Sleep | 0 | | NULL | 0.000 |
+------+--------------+-----------+-----------+---------+------+--------------------------+------------------+----------+
8 rows in set (0.001 sec)
How can I give my SD Card a break? /var/log and /tmp are already on ramdisk (tmpfs)
Then when I continously executed the show processlist command, I also saw the following:
show processlist;
+------+--------------+-----------+-----------+---------+------+--------------------------+------------------------------------------------------------------------------------------------------+----------+
| Id | User | Host | db | Command | Time | State | Info | Progress |
+------+--------------+-----------+-----------+---------+------+--------------------------+------------------------------------------------------------------------------------------------------+----------+
| 1 | system user | | NULL | Daemon | NULL | InnoDB purge coordinator | NULL | 0.000 |
| 2 | system user | | NULL | Daemon | NULL | InnoDB purge worker | NULL | 0.000 |
| 3 | system user | | NULL | Daemon | NULL | InnoDB purge worker | NULL | 0.000 |
| 4 | system user | | NULL | Daemon | NULL | InnoDB purge worker | NULL | 0.000 |
| 5 | system user | | NULL | Daemon | NULL | InnoDB shutdown handler | NULL | 0.000 |
| 2061 | oc_stdcerr13 | localhost | nextcloud | Query | 0 | Init | SELECT `filecache`.`fileid`, `storage`, `path`, `path_hash`, `filecache`.`parent`, `name`, `mimetype | 0.000 |
| 2062 | root | localhost | NULL | Query | 0 | Init | show processlist | 0.000 |
| 2063 | oc_stdcerr13 | localhost | nextcloud | Sleep | 0 | | NULL | 0.000 |
+------+--------------+-----------+-----------+---------+------+--------------------------+------------------------------------------------------------------------------------------------------+----------+
8 rows in set (0.001 sec)
MariaDB [(none)]> show processlist;
+------+--------------+-----------+-----------+---------+------+--------------------------+------------------------------------------------------------------------------------------------------+----------+
| Id | User | Host | db | Command | Time | State | Info | Progress |
+------+--------------+-----------+-----------+---------+------+--------------------------+------------------------------------------------------------------------------------------------------+----------+
| 1 | system user | | NULL | Daemon | NULL | InnoDB purge coordinator | NULL | 0.000 |
| 2 | system user | | NULL | Daemon | NULL | InnoDB purge worker | NULL | 0.000 |
| 3 | system user | | NULL | Daemon | NULL | InnoDB purge worker | NULL | 0.000 |
| 4 | system user | | NULL | Daemon | NULL | InnoDB purge worker | NULL | 0.000 |
| 5 | system user | | NULL | Daemon | NULL | InnoDB shutdown handler | NULL | 0.000 |
| 2061 | oc_stdcerr13 | localhost | nextcloud | Query | 0 | Init | UPDATE `oc_filecache` SET `size` = '-1' WHERE (`fileid` = 15955) AND ((`size` <> '-1') OR (`size` IS | 0.000 |
| 2062 | root | localhost | NULL | Query | 0 | Init | show processlist | 0.000 |
| 2063 | oc_stdcerr13 | localhost | nextcloud | Sleep | 0 | | NULL | 0.000 |
+------+--------------+-----------+-----------+---------+------+--------------------------+------------------------------------------------------------------------------------------------------+----------+
8 rows in set (0.001 sec)
