cinder-backup incremental flag marked as false when volume attached to instance (ceph backend)

[Tzach Shefi]

With an attached Cinder (RBD) volume, incremental backup --force doesn't set is_incremental = true.
I'm guessing back is created as it's available but might be a full backup?

With a none attached volume it works fine.

The error from Cinder's backup log:

2018-04-12 14:30:13.582 1 DEBUG cinder.backup.drivers.ceph [req-927b7483-8df4-4b31-8d4c-d6c158bd4e17 82e9e698e0c34efc856ea8972e30c07a 4adf2dd4b5844ca88db24a01289eaf49 - - -] cmd2='rbd import-diff --id openstack --conf /etc/ceph/ceph.conf --pool backups - backups/volume-364ab166-2cd3-4e53-aa00-315de2f03a66.backup.base' _piped_execute /usr/lib/python2.7/site-packages/cinder/backup/drivers/ceph.py:541
2018-04-12 14:30:13.723 1 INFO cinder.backup.drivers.ceph [req-927b7483-8df4-4b31-8d4c-d6c158bd4e17 82e9e698e0c34efc856ea8972e30c07a 4adf2dd4b5844ca88db24a01289eaf49 - - -] RBD diff op failed - (ret=33 stderr=rbd: import-diff failed: (33) Numerical argument out of domain
)
2018-04-12 14:30:13.723 1 DEBUG cinder.backup.drivers.ceph [req-927b7483-8df4-4b31-8d4c-d6c158bd4e17 82e9e698e0c34efc856ea8972e30c07a 4adf2dd4b5844ca88db24a01289eaf49 - - -] Differential backup transfer failed _backup_rbd /usr/lib/python2.7/site-packages/cinder/backup/drivers/ceph.py:716

Versions:
RHEL7.5
openstack-cinder-12.0.1-0.20180326201852.46c4ec1.el7ost.noarch
puppet-cinder-12.3.1-0.20180222074326.18152ac.el7ost.noarch
python2-cinderclient-3.5.0-1.el7ost.noarch
python-cinder-12.0.1-0.20180326201852.46c4ec1.el7ost.noarch

BTW, Eric managed to reproduce on destack Fedora 27 as well.

Steps to reproduce:

Boot an instance attach a Cinder rbd volume
Create a second none attached volume.

$ cinder backup-create dd873ff7-ff19-4c2c-a3c0-3c660cfd3aac --name FullBackupNoneAttachedVolInc
+-----------+--------------------------------------+
| Property | Value |
+-----------+--------------------------------------+
| id | cf367cd1-8fc1-4bcb-9950-b300a85201e7 |
| name | FullBackupNoneAttachedVolInc |
| volume_id | dd873ff7-ff19-4c2c-a3c0-3c660cfd3aac |
+-----------+--------------------------------------+
$ cidner backup-create dd873ff7-ff19-4c2c-a3c0-3c660cfd3aac --name FullB^CkupNoneAttachedVolInc

$ cinder backup-list
+--------------------------------------+--------------------------------------+-----------+------------------------------+------+--------------+-----------+
| ID | Volume ID | Status | Name | Size | Object Count | Container |
+--------------------------------------+--------------------------------------+-----------+------------------------------+------+--------------+-----------+
| 000baf95-39b3-4441-8c0a-41885c740f18 | dd873ff7-ff19-4c2c-a3c0-3c660cfd3aac | available | FullBackupNoneAttachedVol | 1 | 0 | backups |
| aadf7eb4-df7e-4ee4-969d-fcef1124e84b | 364ab166-2cd3-4e53-aa00-315de2f03a66 | available | FullBackupAttachedVol | 1 | 0 | backups |
| cf367cd1-8fc1-4bcb-9950-b300a85201e7 | dd873ff7-ff19-4c2c-a3c0-3c660cfd3aac | available | FullBackupNoneAttachedVolInc | 1 | 0 | backups |
+--------------------------------------+--------------------------------------+-----------+------------------------------+------+--------------+-----------+

$ cinder backup-create dd873ff7-ff19-4c2c-a3c0-3c660cfd3aac --name FullBackupNoneAttachedVolInc2 --incremental
+-----------+--------------------------------------+
| Property | Value |
+-----------+--------------------------------------+
| id | 3a02b9f2-33d5-423f-baca-659e8311d040 |
| name | FullBackupNoneAttachedVolInc2 |
| volume_id | dd873ff7-ff19-4c2c-a3c0-3c660cfd3aac |
+-----------+--------------------------------------+

$ cinder backup-create 364ab166-2cd3-4e53-aa00-315de2f03a66 --name FullBackupAttachedVolInc2 --incremental --force
+-----------+--------------------------------------+
| Property | Value |
+-----------+--------------------------------------+
| id | 0294ab88-8436-4795-9fce-6e3e479aa88f |
| name | FullBackupAttachedVolInc2 |
| volume_id | 364ab166-2cd3-4e53-aa00-315de2f03a66 |
+-----------+--------------------------------------+

$ cinder backup-list
+--------------------------------------+--------------------------------------+-----------+-------------------------------+------+--------------+-----------+
| ID | Volume ID | Status | Name | Size | Object Count | Container |
+--------------------------------------+--------------------------------------+-----------+-------------------------------+------+--------------+-----------+
| 000baf95-39b3-4441-8c0a-41885c740f18 | dd873ff7-ff19-4c2c-a3c0-3c660cfd3aac | available | FullBackupNoneAttachedVol | 1 | 0 | backups |
| 0294ab88-8436-4795-9fce-6e3e479aa88f | 364ab166-2cd3-4e53-aa00-315de2f03a66 | creating | FullBackupAttachedVolInc2 | 1 | 0 | backups |
| 3a02b9f2-33d5-423f-baca-659e8311d040 | dd873ff7-ff19-4c2c-a3c0-3c660cfd3aac | available | FullBackupNoneAttachedVolInc2 | 1 | 0 | backups |
| aadf7eb4-df7e-4ee4-969d-fcef1124e84b | 364ab166-2cd3-4e53-aa00-315de2f03a66 | available | FullBackupAttachedVol | 1 | 0 | backups |
+--------------------------------------+--------------------------------------+-----------+-------------------------------+------+--------------+-----------+

$ cinder backup-show 0294ab88-8436-4795-9fce-6e3e479aa88f | grep inc
| is_incremental | False |

$ cinder backup-show 3a02b9f2-33d5-423f-baca-659e8311d040 | grep inc
| is_incremental | True |

[Deepa (dpaclt)]

Will there be any fix for this ?

[Eric Harney (eharney)]

Yes, I have a fix I will submit shortly for this issue.

[Eric Harney (eharney)]

This is probably a dupe of https://bugs.launchpad.net/cinder/+bug/1578036 where I have submitted a patch.

https://review.openstack.org/#/c/579606/

[Luigi Toscano (ltoscano)]

Can we close this then?

[Eric Harney (eharney)]

This was ultimately fixed in
https://review.opendev.org/#/c/627941/