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Only the first backend used can create volumes

asked 2013-08-02 14:24:21 -0500

vicethal gravatar image

updated 2013-08-02 18:34:42 -0500

smaffulli gravatar image

Hello,

My OpenStack install is fresh, no instances running. I am tinkering with Cinder. Whenever I create a first volume, it succeeds. However, any volume that would be on a different Physical Volume than the first volume fails to be created. Deleting all of the volumes allows me to successfully use the other backend.

Here's all the background I can think of.

I have two physical volumes on my server: hostname, which is /dev/sda5, and cinder-volumes, /dev/sdb. Both are whole disk PVs. (The hostname PV is partitioned because it is the boot drive.) To match this in Cinder, I have two types of volume: SSD and HDD. Each has its own backend-- Here's my /etc/cinder/cinder.conf:

[DEFAULT]
rootwrap_config = /etc/cinder/rootwrap.conf
sql_connection = mysql://cinderUser:cinderPass@10.0.0.1/cinder
api_paste_confg = /etc/cinder/api-paste.ini
iscsi_helper = ietadm
volume_name_template = volume-%s
#volume_group = cinder-volumes
verbose = True
auth_strategy = keystone
state_path = /var/lib/cinder
lock_path = /var/lock/cinder
volumes_dir = /var/lib/cinder/volumes

# a list of backends that will be served by this machine
enabled_backends=lvmdriver-1,lvmdriver-2

[lvmdriver-1]
volume_group=cinder-volumes
volume_driver=cinder.volume.drivers.lvm.LVMISCSIDriver
volume_backend_name=LVM_HDD
iscsci_helper = ietadm
state_path = /var/lib/cinder
lock_path = /var/lock/cinder
volumes_dir = /var/lib/cinder/volumes

[lvmdriver-2]
volume_group=hostname
volume_driver=cinder.volume.drivers.lvm.LVMISCSIDriver
volume_backend_name=LVM_SSD
iscsci_helper = ietadm
state_path = /var/lib/cinder
lock_path = /var/lock/cinder
volumes_dir = /var/lib/cinder/volumes

(It's a little redundant because I've been messing with it.)

According to instructions in this article: http://docs.openstack.org/trunk/openstack-block-storage/admin/content/multi_backend.html I set up SSD and HDD to refer to the separate disk's PVs:

+--------------------------------------+------+--------------------------------------+
|                  ID                  | Name |             extra_specs              |
+--------------------------------------+------+--------------------------------------+
| 6ce291a3-568e-456b-af8b-bc0306f20570 | HDD  | {u'volume_backend_name': u'LVM_HDD'} |
| b531757b-fc8c-410b-bc99-2178b7ab5f64 | SSD  | {u'volume_backend_name': u'LVM_SSD'} |
+--------------------------------------+------+--------------------------------------+

So I can successfully put an openstack volume onto whichever volume group I choose, but I can only ever have volumes on one at a time, which isn't fun.

Any leads on how to correct this would be greatly appreciated.

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answered 2013-08-02 15:08:36 -0500

vicethal gravatar image

updated 2013-08-02 15:09:00 -0500

I could create and delete volumes freely from either volume group after commenting out these lines in the [DEFAULT] section:

#iscsi_helper = ietadm
#volume_name_template = volume-%s
#volume_group = cinder-volumes

And adding them (unchanged) to both groups. They look essentially identical (with the backend name + bracketed changed) like this:

[lvmdriver-1]
volume_group=cinder-volumes
volume_driver=cinder.volume.drivers.lvm.LVMISCSIDriver
volume_backend_name=LVM_HDD
iscsci_helper = ietadm
state_path = /var/lib/cinder
lock_path = /var/lock/cinder
volumes_dir = /var/lib/cinder/volumes
volume_name_template = volume-%s
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Comments

Not sure but I believe that was a bug in the initial Grizzly release I'd be curious what version you were running there.

jgriffith gravatar imagejgriffith ( 2013-08-15 00:20:22 -0500 )edit

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Asked: 2013-08-02 14:24:21 -0500

Seen: 308 times

Last updated: Aug 02 '13