Ceph » ceph-volume

One can give LVs (logical volumes, each LV will be one slot) and/or physical devices (will be split into slots) to "--db-devices".

Ceph-volume throws a ZeroDivisionError when only LVs are specified as arguments to the "--db-devices" parameter.

The following log shows the issue:

2021-07-05 08:18:36.049906 D | exec: Running command: stdbuf -oL ceph-volume --log-path /tmp/ceph-log lvm batch --prepare --bluestore --yes --dmcrypt --osds-per-device 1 --crush-device-class ssd /dev/sdc /dev/sdd /dev/sda /dev/sdb --db-devices /dev/vg-metadata-0/metadata-0 --report
2021-07-05 08:18:36.814674 D | exec: --> passed data devices: 4 physical, 0 LVM
2021-07-05 08:18:36.814710 D | exec: --> relative data size: 1.0
2021-07-05 08:18:36.814714 D | exec: --> passed block_db devices: 0 physical, 1 LVM
2021-07-05 08:18:36.815635 D | exec: Traceback (most recent call last):
2021-07-05 08:18:36.815646 D | exec:   File "/usr/sbin/ceph-volume", line 11, in <module>
2021-07-05 08:18:36.815650 D | exec:     load_entry_point('ceph-volume==1.0.0', 'console_scripts', 'ceph-volume')()
2021-07-05 08:18:36.815653 D | exec:   File "/usr/lib/python3.6/site-packages/ceph_volume/main.py", line 40, in __init__
2021-07-05 08:18:36.815656 D | exec:     self.main(self.argv)
2021-07-05 08:18:36.815659 D | exec:   File "/usr/lib/python3.6/site-packages/ceph_volume/decorators.py", line 59, in newfunc
2021-07-05 08:18:36.815661 D | exec:     return f(*a, **kw)
2021-07-05 08:18:36.815663 D | exec:   File "/usr/lib/python3.6/site-packages/ceph_volume/main.py", line 152, in main
2021-07-05 08:18:36.815666 D | exec:     terminal.dispatch(self.mapper, subcommand_args)
2021-07-05 08:18:36.815668 D | exec:   File "/usr/lib/python3.6/site-packages/ceph_volume/terminal.py", line 194, in dispatch
2021-07-05 08:18:36.815670 D | exec:     instance.main()
2021-07-05 08:18:36.815673 D | exec:   File "/usr/lib/python3.6/site-packages/ceph_volume/devices/lvm/main.py", line 42, in main
2021-07-05 08:18:36.815675 D | exec:     terminal.dispatch(self.mapper, self.argv)
2021-07-05 08:18:36.815677 D | exec:   File "/usr/lib/python3.6/site-packages/ceph_volume/terminal.py", line 194, in dispatch
2021-07-05 08:18:36.815680 D | exec:     instance.main()
2021-07-05 08:18:36.815682 D | exec:   File "/usr/lib/python3.6/site-packages/ceph_volume/decorators.py", line 16, in is_root
2021-07-05 08:18:36.815684 D | exec:     return func(*a, **kw)
2021-07-05 08:18:36.815687 D | exec:   File "/usr/lib/python3.6/site-packages/ceph_volume/devices/lvm/batch.py", line 402, in main
2021-07-05 08:18:36.815689 D | exec:     plan = self.get_plan(self.args)
2021-07-05 08:18:36.815692 D | exec:   File "/usr/lib/python3.6/site-packages/ceph_volume/devices/lvm/batch.py", line 440, in get_plan
2021-07-05 08:18:36.815694 D | exec:     args.wal_devices)
2021-07-05 08:18:36.815698 D | exec:   File "/usr/lib/python3.6/site-packages/ceph_volume/devices/lvm/batch.py", line 472, in get_deployment_layout
2021-07-05 08:18:36.815701 D | exec:     fast_type)
2021-07-05 08:18:36.815704 D | exec:   File "/usr/lib/python3.6/site-packages/ceph_volume/devices/lvm/batch.py", line 514, in fast_allocations
2021-07-05 08:18:36.815707 D | exec:     if (requested_osds - len(lvm_devs)) % len(phys_devs):
2021-07-05 08:18:36.815710 D | exec: ZeroDivisionError: integer division or modulo by zero
failed to configure devices: failed to initialize lvm based osd: failed ceph-volume report: exit status 1

I have prepared a PR that fixes this issue.