May corrupt filesystem in Guest when parent vmdk having streamOptimized type

[mory]

Hi,

I'm wondering for a long time why guest filesystem sometime corrupt.

(Often occured when remove temporary snapshot,)

But now, I found a cause.

When one or more of parent snapshot's vmdk had streamOptimized (current snapshot's vmdk is ordinary monolithicSparse), it is very dangerous.

If Windows 10 Guest with parent having streamOptimized, defrag C: & chkdsk C: /f & shutdown -r -t 0 will/may report filesystem corruption in event viewer.

Reconvert all of parent snapshot's vmdk type from streamOptimized to monolithicSparse, above commands works fine without filesystem corruption.

(Tested on VMware Workstation 11.1.4.)

[continuum]

The streamOptimized variant of the monolithicSparse VMDK-type was never meant to be used like that.
It was designed as a space-efficient form to move large VMDKs from one platform to another.
At the time it appeared the vmware-vdiskmanager tool was still functional so occasional errors were fixable.
Nowadays small errors in monolithicSparse often result in a complete loss - so be careful.
Dont use streamOptimized for anything else but transports. Even here I would rather zip what you have in regular use - and try to avoid this format completely.