This isn't really a bug, and there is a blueprint for this with some discussion:
https://blueprints.launchpad.net/nova/+spec/nova-improvement-of-maximum- attach-volumes-more-than-26-vols ** Changed in: nova Status: New => Incomplete ** Changed in: nova Status: Incomplete => Opinion ** Changed in: nova Importance: Undecided => Wishlist -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to OpenStack Compute (nova). https://bugs.launchpad.net/bugs/1773941 Title: Not able to attach more than 25 volumes using virtio-scsi Status in OpenStack Compute (nova): Opinion Bug description: Not able to attach more than 25 volumes using virtio-scsi In nova/virt/libvirt/blockinfo.py, def get_dev_count_for_disk_bus(disk_bus): """Determine the number disks supported. Determine how many disks can be supported in a single VM for a particular disk bus. Returns the number of disks supported. """ if disk_bus == "ide": return 4 else: return 26 <=== we're just responding with 26 devices that we can use. and def find_disk_dev_for_disk_bus(mapping, bus, last_device=False, assigned_devices=None): """Identify a free disk dev name for a bus. Determines the possible disk dev names for the bus, and then checks them in order until it identifies one that is not yet used in the disk mapping. If 'last_device' is set, it will only consider the last available disk dev name. Returns the chosen disk_dev name, or raises an exception if none is available. """ dev_prefix = get_dev_prefix_for_disk_bus(bus) if dev_prefix is None: return None if assigned_devices is None: assigned_devices = [] max_dev = get_dev_count_for_disk_bus(bus) if last_device: devs = [max_dev - 1] else: devs = range(max_dev) for idx in devs: disk_dev = dev_prefix + chr(ord('a') + idx) <====== need to correct naming of devices if not has_disk_dev(mapping, disk_dev): if disk_dev not in assigned_devices: return disk_dev raise exception.NovaException( _("No free disk device names for prefix '%s'") % dev_prefix) To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1773941/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp