On Wed, May 16, 2018 at 9:15 AM Mark Stodola <[log in to unmask]> wrote:

> On 05/15/2018 08:53 PM, Lofgren, Eric wrote:
> > Having failed to fix the ugly partition system, we’re going for
reconfiguring mysql to make it elsewhere. I followed this post to try to
get the temporary directory to point to another partition:
https://encylia.com/2015/02/06/how-to-change-the-mysql-tmp-location-on-centos/
by doing all of the following under sudo:
> >
> > mkdir /home/mysqltmp
> > chmod 1777 /home/mysqltmp
> >
> > nano /etc/my.cnf
> >
> > Add below line under the [mysqld] section and save the file:
> > tmpdir=/home/mysqltmp
> >
> > systemctl restart mysqld
> >
> > This restart fails. If I restore the old my.cnf without the change, it
works perfectly. Checking the log, it seems there’s a permissions issue:
> >
> > 2018-05-16T00:01:05.211853Z 0 [Note] /usr/sbin/mysqld (mysqld 5.7.22)
starting as process 5929 ...
> > 2018-05-16T00:01:05.214159Z 0 [Note] InnoDB: PUNCH HOLE support
available
> > 2018-05-16T00:01:05.214186Z 0 [Note] InnoDB: Mutexes and rw_locks use
GCC atomic builtins
> > 2018-05-16T00:01:05.214191Z 0 [Note] InnoDB: Uses event mutexes
> > 2018-05-16T00:01:05.214194Z 0 [Note] InnoDB: GCC builtin
__atomic_thread_fence() is used for memory barrier
> > 2018-05-16T00:01:05.214197Z 0 [Note] InnoDB: Compressed tables use zlib
1.2.3
> > 2018-05-16T00:01:05.214202Z 0 [Note] InnoDB: Using Linux native AIO
> > 2018-05-16T00:01:05.214382Z 0 [Note] InnoDB: Number of pools: 1
> > 2018-05-16T00:01:05.214459Z 0 [Note] InnoDB: Using CPU crc32
instructions
> > mysqld: Can't create/write to file '/home/mysqltmp/ibAcknwl' (Errcode:
13 - Permission denied)
> > 2018-05-16T00:01:05.214535Z 0 [ERROR] InnoDB: Unable to create
temporary file; errno: 13
> > 2018-05-16T00:01:05.214542Z 0 [ERROR] InnoDB: Plugin initialization
aborted with error Generic error
> > 2018-05-16T00:01:05.214548Z 0 [ERROR] Plugin 'InnoDB' init function
returned error.
> > 2018-05-16T00:01:05.214551Z 0 [ERROR] Plugin 'InnoDB' registration as a
STORAGE ENGINE failed.
> > 2018-05-16T00:01:05.214554Z 0 [ERROR] Failed to initialize builtin
plugins.
> > 2018-05-16T00:01:05.214557Z 0 [ERROR] Aborting
> >
> > Any clues as to what I’ve done wrong?
> >
> > Thanks,
> > Eric
> >

> Moving the temporary file location is a bandage.  You really should be
> concerned with the full root partition.  It is going to affect the
> operation of more than just mysql.

This is *exactly* why many folks make /var/limysql a mountpoint to some
bulky attached storage, to avoid having to reconfigure their MySQL. It's
helpful to move aside the old directory, and make a n ew directory with
permissions 000 to ensure that failure to mount the directory does not
leave an almost-kind-of-running MySQL on system startup.