Create volume from image fails on Dell EQL driver

[Tzach Shefi]

Description of problem: Fail to create cinder volume from Glance image, with Cinder Dell EQL storage driver/backend. Empty volumes are created successfully

ERROR cinder.volume.flows.manager.create_volume [req-67a1a22e-f7b7-49e4-a365-f66e58026904 3421d84131ca4385af185e04e2cb3d11 b5678896173d4959a3190f7ca17d886a - - -] Failed to copy image 58a8d212-7ecf-4d8a-b07c-94d879fadb52 to volume: b03d7bba-5dcb-4735-af42-cb8783f8da33, error: Volume device not found at /dev/disk/by-path/ip-10.16.45.61:3260-iscsi-iqn.2001-05.com.equallogic:0-8a0906-4d06b4906-0030073ce8853fee-volume-b03d7bba-5dcb-4735-af42-cb8783f8da33-lun-0.
2014-08-28 11:14:43.076 29860 DEBUG cinder.volume.flows.common [req-67a1a22e-f7b7-49e4-a365-f66e58026904 3421d84131ca4385af185e04e2cb3d11 b5678896173d4959a3190f7ca17d886a - - -] Updating volume: b03d7bba-5dcb-4735-af42-cb8783f8da33 with {'status': 'error'} due to: ??? error_out_volume /usr/lib/python2.7/site-packages/cinder/volume/flows/common.py:87
2014-08-28 11:14:43.114 29860 ERROR cinder.volume.flows.manager.create_volume [req-67a1a22e-f7b7-49e4-a365-f66e58026904 3421d84131ca4385af185e04e2cb3d11 b5678896173d4959a3190f7ca17d886a - - -] Volume b03d7bba-5dcb-4735-af42-cb8783f8da33: create failed
...

2014-08-28 11:14:43.115 29860 TRACE oslo.messaging.rpc.dispatcher raise exception.ImageCopyFailure(reason=ex)
2014-08-28 11:14:43.115 29860 TRACE oslo.messaging.rpc.dispatcher ImageCopyFailure: Failed to copy image to volume: Volume device not found at /dev/disk/by-path/ip-10.16.45.61:3260-iscsi-iqn.2001-05.com.equallogic:0-8a0906-4d06b4906-0030073ce8853fee-volume-b03d7bba-5dcb-4735-af42-cb8783f8da33-lun-0.
2014-08-28 11:14:43.115 29860 TRACE oslo.messaging.rpc.dispatcher

Version-Release number of selected component (if applicable):
RHEL7
python-cinder-2014.1.2-2.el7ost.noarch
openstack-cinder-2014.1.2-2.el7ost.noarch
python-cinderclient-1.0.9-1.el7ost.noarch
openstack-glance-2014.1.2-1.el7ost.noarch
python-glance-2014.1.2-1.el7ost.noarch
python-glanceclient-0.13.1-1.el7ost.noarch
Dell EQL PS6000 storage

How reproducible:
Every time

Steps to Reproduce:
1. Setup AIO, (my setup also included Nova live migration over NFS share, not related just mentioning the fact)
2. Configure Cinder to use EQL driver
3. Try to create a new volume from Glance image, fails status = error, Volume on log search for -> b03d7bba-5dcb-4735-af42-cb8783f8da33).
4. Create an empty Cinder volume, successfully created.

Actual results:
Failed to create volume from Glance image, volumes status=error

Expected results:
Should successfully create a Cinder volume from Glance image, as happens with Cinder LVM.

[Rajini Karthik (rajini-karthik)]

Please, configure:

num_volume_device_scan_tries=5

in your cinder.conf, it will work.

It's default value is 3 which is not enough in your particular case. Your environment is too slow, it takes time for new device to appear under /dev/disk/by-path/... meantime after 3 retries system declares that destination images doesn't exist and stops operation.

[Tzach Shefi (tshefi)]

Rajini's suggested fix above resolved my problem.