The OpenStack Block Storage service is the volume manager service of OpenStack. It provides storage volumes from the underlying storage provider and provides the ability to attach the volumes to the OpenStack virtual machine instances running on the compute node. By default, the Block Storage service uses the Linux native LVM provider for carving out volumes. 

Cinder services store their log files in the /var/log/cinder directory.

To check if all the cinder services are running, invoke the following command:

# ps -aux | grep cinder
stack 1015 0.3 2.5 356060 104432 ? Ss 04:28 0:19 /usr/bin/python /usr/local/bin/cinder-scheduler --config-file /etc/cinder/cinder.conf
stack 1019 0.0 0.0 92252 3980 ? Ss 04:28 0:00 cinder-apiuWSGI master
stack 1027 2.5 1.3 354572 53608 ? Ss 04:28 2:07 /usr/bin/python /usr/local/bin/cinder-volume --config-file /etc/cinder/cinder.conf
stack 1577 0.1 2.8 448804 116956 ? Sl 04:28 0:07 cinder-apiuWSGI worker 1
stack 1578 0.0 2.9 373696 119184 ? S 04:28 0:04 cinder-apiuWSGI worker 2
stack 2712 1.9 2.6 356796 108132 ? S 04:29 1:34 /usr/bin/python /usr/local/bin/cinder-volume --config-file /etc/cinder/cinder.conf

You  may find several instances of each cinder process running. Essentially, the following services should be running:

• cinder-api
• cinder-scheduler
• cinder-volume

If any of the preceding services are not running, you may start them manually by invoking the respective commands:

sudo -u cinder cinder-api --config-file=/etc/cinder/cinder.conf --log-file=/var/log/cinder/cinder-api.log
sudo -u cinder cinder-scheduler --config-file=/etc/cinder/cinder.conf --log-file=/var/log/cinder/cinder-scheduler.log
sudo -u cinder cinder-volume --config-file=/etc/cinder/cinder.conf --log-file=/var/log/cinder/cinder-volume.log

Now, lets look at some common issues that are encountered with the cinder volume service.