rbd块映射

rbd块映射：

 root@u18:~# rbd create kvm/test002.img --size
 root@u18:~# rbd info kvm/test002.img
 rbd image 'test002.img':
     size  kB in  objects
     order  ( kB objects)
     block_name_prefix: rb..2f13.2ae8944a
     format:
 root@u18:~# rbd map kvm/test002.img
 root@u18:~# lsblk
 NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
 sda      :     .1G   disk
 ├─sda1   :     .2G   part /
 ├─sda2   :         1K   part
 └─sda5   :       .9G   part [SWAP]
 sdb      :    .8G   disk
 ├─sdb1   :      200G   part /ceph_node0
 ├─sdb2   :        1K   part
 ├─sdb5   :      100G   part
 └─sdb6   :    .8G   part /data2
 rbd0   :        40G   disk
 rbd1   :       20M   disk
 zram0  :     936.4M   disk [SWAP]

 root@u18:~# mkfs.ext4 /dev/rbd1
 mke2fs 1.42 (-Nov-)
 Filesystem label=
 OS type: Linux
 Block size= (log=)
 Fragment size= (log=)
 Stride= blocks, Stripe width= blocks
  inodes,  blocks
  blocks (5.00%) reserved for the super user
 First data block=
 Maximum filesystem blocks=
  block groups
  blocks per group,  fragments per group
  inodes per group
 Superblock backups stored on blocks: 

 Allocating group tables: done
 Writing inode tables: done
 Creating journal ( blocks): done
 Writing superblocks and filesystem accounting information: done

 root@u18:~# mount /dev/rbd1 /mnt
 root@u18:~# echo test > /mnt/a.log
 root@u18:~# vim a.log
 root@u18:~# vim /mnt/a.log
 root@u18:~# umount /mnt
 root@u18:~# rbd unmap /dev/rbd1
 root@u18:~# rbd resize --size  kvm/test002.img
 Resizing image: % complete...done.
 root@u18:~# rbd info kvm/test002.img
 rbd image 'test002.img':
     size  MB in  objects
     order  ( kB objects)
     block_name_prefix: rb..2f13.2ae8944a
     format:
 root@u18:~# rbd info kvm/test002.img
 rbd image 'test002.img':
     size  MB in  objects
     order  ( kB objects)
     block_name_prefix: rb..2f13.2ae8944a
     format:
 root@u18:~# rbd map kvm/test002.img
 root@u18:~# lsblk
 NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
 sda      :     .1G   disk
 ├─sda1   :     .2G   part /
 ├─sda2   :         1K   part
 └─sda5   :       .9G   part [SWAP]
 sdb      :    .8G   disk
 ├─sdb1   :      200G   part /ceph_node0
 ├─sdb2   :        1K   part
 ├─sdb5   :      100G   part
 └─sdb6   :    .8G   part /data2
 rbd0   :        40G   disk
 rbd1   :       40G   disk
 zram0  :     936.4M   disk [SWAP]
 root@u18:~# rbd unmap /dev/rbd1
 root@u18:~# lsblk
 NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
 sda      :     .1G   disk
 ├─sda1   :     .2G   part /
 ├─sda2   :         1K   part
 └─sda5   :       .9G   part [SWAP]
 sdb      :    .8G   disk
 ├─sdb1   :      200G   part /ceph_node0
 ├─sdb2   :        1K   part
 ├─sdb5   :      100G   part
 └─sdb6   :    .8G   part /data2
 rbd0   :        40G   disk
 zram0  :     936.4M   disk [SWAP]
 root@u18:~# rbd map kvm/test002.img
 root@u18:~# lsblk
 NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
 sda      :     .1G   disk
 ├─sda1   :     .2G   part /
 ├─sda2   :         1K   part
 └─sda5   :       .9G   part [SWAP]
 sdb      :    .8G   disk
 ├─sdb1   :      200G   part /ceph_node0
 ├─sdb2   :        1K   part
 ├─sdb5   :      100G   part
 └─sdb6   :    .8G   part /data2
 rbd0   :        40G   disk
 rbd1   :       40G   disk
 zram0  :     936.4M   disk [SWAP]
 root@u18:~# mount /dev/rbd1 /mnt
 root@u18:~# parted /dev/rbd1  print free
 root@u18:~# parted /dev/rbd1  print free
 Model: Unknown (unknown)
 Disk /dev/rbd1: .9GB
 Sector size (logical/physical): 512B/512B
 Partition Table: loop

 Number  Start  End     Size    File system  Flags
        .00B  .9GB  .9GB  ext4

 root@u18:~# vim /mnt/a.log
 root@u18:~# cat /mnt/a.log
 test