理解 QEMU/KVM 和 Ceph（3）：存储卷挂接和设备名称

#运行nova-attach 命令

nova volume-attach INSTANCE_ID VOLUME_ID auto



#在虚机中操作

vm$ ls /dev/disk/by-id/
virtio-15a9f901-ba9d-45e1-8
vm$ mkfs.ext4 /dev/disk/by-id/virtio-15a9f901-ba9d-45e1-8
vm$ mkdir -p /mnt/volume
vm$ mount /dev/disk/by-id/virtio-15a9f901-ba9d-45e1-8 /mnt/volume
vm$ echo "Hello OpenStack" > /mnt/volume/test.txt

#在虚机中操作

vm$ umount /mnt/volume



#运行 Nova 命令
$ nova volume-detach <instanceid> <volumeid>

root@hkg02kvm004ccz023:~# nova help volume-attach
usage: nova volume-attach <server> <volume> [<device>]

Attach a volume to a server.
Positional arguments:
  <server>  Name or ID of server.
  <volume>  ID of the volume to attach.
  <device>  Name of the device e.g. /dev/vdb. Use "auto" for autoassign (if supported). Libvirt driver will use default device name.

root@hkg02kvm004ccz023:~# nova volume-attach ap-uplthyfxulbx 8a309ad1-369c-483b-9a95-e4f330bb104e /dev/vdh
+----------+--------------------------------------+
| Property | Value                                |
+----------+--------------------------------------+
| device   | /dev/vdh                             |

[root@ap-4oe4-4rz25pvadal7-cs7nmsu4izfy-server-uplthyfxulbx rules.d]# fdisk -l

Disk /dev/vda: 42.9 GB, 42949672960 bytes
...
Disk /dev/vdb: 1073 MB, 1073741824 bytes
...
Disk /dev/vdc: 2147 MB, 2147483648 bytes
...
Disk /dev/vdd: 3221 MB, 3221225472 bytes
...

[root@ap-4oe4-4rz25pvadal7-cs7nmsu4izfy-server-uplthyfxulbx ibmcloud]# udevadm info -a -n /dev/vdb

  looking at device '/devices/pci0000:00/0000:00:07.0/virtio3/block/vdb':
    KERNEL=="vdb"
    SUBSYSTEM=="block"
    DRIVER==""
    ...
  looking at parent device '/devices/pci0000:00/0000:00:07.0/virtio3':
    KERNELS=="virtio3"
    SUBSYSTEMS=="virtio"
    DRIVERS=="virtio_blk"
    ...
  looking at parent device '/devices/pci0000:00/0000:00:07.0':
    KERNELS=="0000:00:07.0"
    SUBSYSTEMS=="pci"
    DRIVERS=="virtio-pci"
    ...
  looking at parent device '/devices/pci0000:00':
    KERNELS=="pci0000:00"
    SUBSYSTEMS==""
    DRIVERS==""

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)
        if not has_disk_dev(mapping, disk_dev):
            if disk_dev not in assigned_devices:
                return disk_dev

[ibmcloud@ap-4oe4-4rz25pvadal7-cs7nmsu4izfy-server-uplthyfxulbx ~]$ ls -l /dev/disk
total 0
drwxr-xr-x 2 root root 100 Mar 27 07:16 by-id
drwxr-xr-x 2 root root 140 Mar 27 07:16 by-path
drwxr-xr-x 2 root root  80 Mar 27 07:16 by-uuid

[ibmcloud@ap-4oe4-4rz25pvadal7-cs7nmsu4izfy-server-uplthyfxulbx ~]$ ls -l /dev/disk/by-uuid/
total 0
lrwxrwxrwx 1 root root 10 Mar 27 07:16 002f642d-f277-49fd-b5ff-47a652b63fe3 -> ../../vda1
lrwxrwxrwx 1 root root  9 Mar 27 07:16 1655a8ca-9627-4a81-acca-79fec66e1131 -> ../../vdb

[ibmcloud@ap-4oe4-4rz25pvadal7-cs7nmsu4izfy-server-uplthyfxulbx ~]$ ls -l /dev/disk/by-id/
total 0
lrwxrwxrwx 1 root root 9 Mar 27 07:16 virtio-6e5424e4-4e4c-4178-a -> ../../vdb
lrwxrwxrwx 1 root root 9 Mar 27 07:16 virtio-8a309ad1-369c-483b-9 -> ../../vdd
lrwxrwxrwx 1 root root 9 Mar 27 07:16 virtio-e4585a93-9a90-4967-8 -> ../../vdc

root@hkg02kvm004ccz023:~#  cinder list | grep 6e5424e4-4e4c-4178-a
| 6e5424e4-4e4c-4178-a4cc-e63698716e9b |      in-use     |                      sammyvol3                      |  2   |      None     |  false   | 9ca18b9e-aeef-44ff-81ba-87a59a0c8eec |

# virtio-blk
KERNEL=="vd*[!0-9]", ATTRS{serial}=="?*", ENV{ID_SERIAL}="$attr{serial}", SYMLINK+="disk/by-id/virtio-$env{ID_SERIAL}"
KERNEL=="vd*[0-9]", ATTRS{serial}=="?*", ENV{ID_SERIAL}="$attr{serial}", SYMLINK+="disk/by-id/virtio-$env{ID_SERIAL}-part%n"

<disk type='file' device='disk'>
      <driver name='qemu' type='qcow2' cache='none'/>
      <source file='/opt/stack/data/nova/instances/9ca18b9e-aeef-44ff-81ba-87a59a0c8eec/disk'/>
      <target dev='vda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </disk>

[ibmcloud@ap-4oe4-4rz25pvadal7-cs7nmsu4izfy-server-uplthyfxulbx ~]$ ls -l /dev/disk/by-path/
total 0
lrwxrwxrwx 1 root root  9 Mar 27 07:16 pci-0000:00:04.0-virtio-pci-virtio1 -> ../../vda
lrwxrwxrwx 1 root root 10 Mar 27 07:16 pci-0000:00:04.0-virtio-pci-virtio1-part1 -> ../../vda1
lrwxrwxrwx 1 root root  9 Mar 27 07:16 pci-0000:00:06.0-virtio-pci-virtio3 -> ../../vdb
lrwxrwxrwx 1 root root  9 Mar 27 07:16 pci-0000:00:07.0-virtio-pci-virtio4 -> ../../vdc
lrwxrwxrwx 1 root root  9 Mar 27 07:16 pci-0000:00:08.0-virtio-pci-virtio5 -> ../../vdd

# by-path (parent device path)
ENV{DEVTYPE}=="disk", ENV{ID_PATH}=="", IMPORT{program}="path_id %p"
ENV{DEVTYPE}=="disk", ENV{ID_PATH}=="?*", SYMLINK+="disk/by-path/$env{ID_PATH}"
ENV{DEVTYPE}=="partition", ENV{ID_PATH}=="?*", SYMLINK+="disk/by-path/$env{ID_PATH}-part%n"

    本文转自SammyLiu博客园博客，原文链接：http://www.cnblogs.com/sammyliu/p/5325492.html，如需转载请自行联系原作者