Cannot start MySQL service on linux RHEL when pointing datadir to mounted ecryptfs folder

Question

I moved the data directory for MySQL to an ecryptfs encrypted folder. When I run service mysqld start as root, the service will not start.

[Warning] Can't create test file /mysql/ip-172-31-29-184.lower-test
^G/usr/sbin/mysqld: Can't change dir to '/mysql/' (Errcode: 13 - Permission denied)

When it used to start before my encrypting the folder

ls -lZ /mysql outputs
drwx------. mysql mysql unconfined_u:object_r:mysqld_db_t:s0 mysql

now

ls -lZ /mysql outputs
drwx------. mysql mysql system_u:object_r:ecryptfs_t:s0 mysql

I think the issue is with how I mounted the encrypted directory.
mount -t ecryptfs /mysql /mysql

mount outputs

/mysql on /mysql type ecryptfs
 (rw,ecryptfs_sig=6860c372da7bc418,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_unlink_sigs)

I am running Red Hat Enterprise Linux Server release 6.6 (Santiago), MySQL 5.6.22

Any advice is appreciated. Thank you for your help in advance.

• Nawaz Sohail: does it work well without encryption?.. i think you may need to change ownership recursively using chown -R mysql:mysql for whole directories and then can try.
• Grace: Thank you for your comment. Yes, it works if I don't use encryption. The folder and sub directories are all owned by mysql.
• Fiisch: Looks like you have bad selinux labels on the folder. Before encryption I see mysqld_db_t and after encryption this is gone. Instead of it ecryptfs_t is present. Try turning selinux off or better - set it temporarily into permissive mode with setenforce 0. If mysql starts, check selinux logs what it is complainging about.

Answer 1

Make sure the MySQL server owner is MySQL:MySQL using chown -R mysql:mysql /mysql and the permission level is 755 for everything except my.cnf 644. chmod 644 my.cnf then execute the following commands after changing the information inside my.cnf to the correct one.

cd /mysql/bin
./mysqld --defaults-file=/mysql/my.cnf --user=mysql &

Edit to answer the comment below To shutdown MySQL safely without killing the SID (or PID) you can use one of the following commands:

/usr/local/mysql/bin/mysqladmin -u root -p shutdown 

or

sudo mysqld stop

note: in-case you can more than SID running you need to specify the port for it.

• Grace: Hi Ahmad, Thank you for your suggestion. I changed the permission for /mysql to 755. The owner and group are mysql:mysql There is no bin folder in /mysql. /mysql is my data directory is and I modified /etc/my.cfn (datadir=/mysql) to point to that. I tried starting the service after the permission change but I am still getting the same error. Here is a listing of what is in /mysql folder. -rwxr-xr-x. 1 mysql mysql 56 Dec 23 00:00 auto.cnf drwxr-xr-x. 2 mysql mysql 4096 Dec 23 00:00 mysql drwxr-xr-x. 2 mysql mysql 4096 Dec 23 00:00 performance_schema Thank you again.
• Ahmad Abuhasna: did you installed MySQL via yum or apt-get command? or extract the compressed file?
• Grace: Hi Ahmad, Thank you! I installed via yum and I found the mysqld file to start it. This worked - ./mysqld --defaults-file=/etc/my.cnf --user=mysql &
• Grace: Hi Ahmad, how do I safely shutdown this instance of mysql short of using killing the pid? Is there anyway I can start mysql for the encrypted folders using the service mysqld commands? Thank you.
• Ahmad Abuhasna: Hi Grace, please refer to my edit in the answer section above