目标:10T的碎文件(10k-500k)数据需要局域网从一台存储迁移到另一台存储

方案：采用基于drbd软件迁移扩容方案

提示：主节点10T，备节点20T，如果采用drbd同步方案，同步后备用节点和主节点一样大小。备节点的剩余10T看不到也无法使用。

问题：

主节点，备节点是2.0G，备节点是2.0G（实际应该是3G，通过df -h命令只能看到2G）

[root@nfs-server-01 teddylu]# df -h|grep md0

/dev/drbd0 2.0G 3.0M 1.9G 1% /md0



[root@nfs-server-02 teddylu]# df -h|grep md0

/dev/md0 2.0G 3.0M 1.9G 1% /md0



[root@nfs-server-02 teddylu]# fdisk -l|grep /dev/md0

Disk /dev/md0: 3205 MB, 3205496832 bytes

 

原因：

因为drbd是基于block的复制，所以备节点上的的size会和主节点一模一样。

解决：

[root@nfs-server-02 teddylu]# umount /md0/

[root@nfs-server-02 teddylu]# drbdadm down data



[root@nfs-server-02 teddylu]# e2fsck -f /dev/md0???????

e2fsck 1.41.12 (17-May-2010)

Pass 1: Checking inodes, blocks, and sizes

Pass 2: Checking directory structure

Pass 3: Checking directory connectivity

Pass 4: Checking reference counts

Pass 5: Checking group summary information

/dev/md0: 21/130560 files (0.0% non-contiguous), 17164/521472 blocks

[root@nfs-server-02 teddylu]# resize2fs /dev/md0

resize2fs 1.41.12 (17-May-2010)

Resizing the filesystem on /dev/md0 to 782592 (4k) blocks.

The filesystem on /dev/md0 is now 782592 blocks long.



[root@nfs-server-02 teddylu]# mount /dev/md0 /md0/

[root@nfs-server-02 teddylu]# df -h

Filesystem Size? Used Avail Use% Mounted on

/dev/sda2 7.8G? 3.5G? 3.9G? 48% /

tmpfs 242M???? 0? 242M?? 0% /dev/shm

/dev/sda1 190M?? 49M? 132M? 28% /boot

/dev/md0 3.0G 3.0M 2.8G 1% /md0

此时，备节点的size是显示为正常的3G了

提示

e2fsck – check a Linux ext2/ext3/ext4 file system

-f Force checking even if the file system seems clean.

resize2fs – ext2/ext3/ext4 file system resizer

 The resize2fs program will resize ext2, ext3, or ext4 file systems.? It can be used to enlarge or shrink an unmounted file system located on device。