The parent virtual disk has been modified since the child was created
Problem：
具体的消息是：
Failed to start the virtual machine.
Module DiskEarly power on failed.
Cannot open the disk '/vmfs/volumes/54627907-c2477c60-ec2b-0024e8573a7f/WebServer_Version2/WebServer_Version 2-000008.vmdk' or one of the snapshot disks it depends on.
The parent virtual disk hasbeen modified since the child was created. The content ID of the parent virtual disk doesnot match the corresponding parent content ID in the child
解决方法参考:
解决方法和思路：
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1. 先开启任意一个机器上的SSH服务
2. 然后用ssh 登录到这个ESXI计算机上
3. 运行下面的命令
Cat WebServer_Version\ 2.vmdk
------------------------------------------------------------
# Disk DescriptorFile
version=1
encoding="UTF-8"
CID=60025a0a
parentCID=ffffffff
isNativeSnapshot="no"
createType="vmfs"
# Extent description
RW 167772160 VMFS "WebServer_Version 2-flat.vmdk"
# The Disk Data Base
#DDB
ddb.adapterType = "lsilogic"
ddb.deletable = "true"
ddb.geometry.cylinders = "10443"
ddb.geometry.heads = "255"
ddb.geometry.sectors = "63"
ddb.longContentID ="4335f3cc11a7c8500cdb139a60025a0a"
ddb.uuid = "60 00 C2 99 f5 15 36 81-06 e3 f8 b6 66 dc30 de"
ddb.virtualHWVersion = "8"
/vmfs/volumes/54627907-c2477c60-ec2b-0024e8573a7f/WebServer_Version2 # cat WebServer_Version\ 2-000008.vmdk
# Disk DescriptorFile
version=1
encoding="UTF-8"
CID=7e05ba5d
parentCID=75d5382b
createType="vmfsSparse"
parentFileNameHint="WebServer_Version 2.vmdk"
# Extent description
RW 167772160 VMFSSPARSE "WebServer_Version2-000008-delta.vmdk"
# The Disk Data Base
#DDB
ddb.longContentID = "901af6c76efda040f8d76a817e05ba5d"
4. 在检查的vmdk中，我们可以看到parentCID是和上面的CID不一样的。
5. 然后把备份这个文件夹通过下载的方法
6. 编辑WebServer_Version\ 2-000008.vmdk中的ParentCID为60025a0a
P.S.
在ESXI中所有的VM都存放在/vmfs/volumes下面，后面的一串ID是和我们建立存储的friendly的一个硬连接
本文转自 zhangfang526 51CTO博客，原文链接:http://blog.51cto.com/zhangfang526/1787202