Mysql database in a symlink-ed directory gives ERROR 1005 (errorno: 13)

I've the need to put my database outside the default datadir of mysql.

To achieve that I followed the symlink guidance in the mysql documentation.

However when I use the db if I try to create a table I'm greeted with:

ERROR 1005 (HY000): Can't create table 'test' (errno: 13)

In my search for solutions I already read Can I use symlink or data directory for ARCHIVE MySQL tables? and this answer which didn't apply for my context.

At the moment my data dir looks like this with ls -Ll

server:/var/lib/mysql# ls -Ll
total 28800
-rw-r--r-- 1 root  root         0 Jan 26 00:37 debian-5.5.flag
-rw-rw---- 1 mysql mysql    25088 Feb  8  2005 ib_arch_log_0000000000
-rw-rw---- 1 mysql mysql 18874368 May 31 15:21 ibdata1
-rw-rw---- 1 mysql mysql  5242880 May 31 15:21 ib_logfile0
-rw-rw---- 1 mysql mysql  5242880 Feb  8  2005 ib_logfile1
drwx------ 2 mysql mysql     4096 Jan 26 00:37 mysql
drwxr-xr-x 1 root  root         0 May 29 00:01 so
drwx------ 2 mysql mysql     4096 May 28 22:48 so2
drwxr-xr-x 2 mysql mysql      4096 May 31 14:34 symlink
drwxr-xr-x 2 mysql mysql     4096 Apr 20  2013 test

The two symlinks are created with the command

ln -s /mnt/nas/se/data/mysql/ so

I chown the symlinks to mysql:mysql as well as in the directory it self. For the symlink directory that worked (that is on an ext3 fs) but for the so one (that is on a nas over CIFS/SMB) I'm still out of luck.

I managed to enable NFS (ver 3) on the NAS (running BusyBox v1.1.1) and mounted that as well. I synced the UID for the mysql account on the server and the client. Unfortunately the result is the same for ls -Ll

drwxrwxr-x 2 root  rene      4096 May 31 16:51 sonfs

and for ls -l

lrwxrwxrwx 1 root  root         8 Jun  1 00:26 sonfs -> /mnt/nfs

I did su mysql and tried to cp a file to those symlinked directories and that worked which made me assume on the OS level the permissions are OK.

Within mysql I granted root all permissions to the so and the symlink database.

I'm not sure if I the problem I face is something I misconfigured at the Debian OS level or within mysql itself.

Can someone point out to me what diagnosis I need to do and which steps need to be taken to be able to create tables that get stored in those symlinked directories?