Problem taking snapshot with vmdk disk

[NA!]

I have a vmware VM on an esxi 5.1 server. I have downloaded the main vmdk and am trying to use it in latest vbox. I have created a new vm and added the vmdk to it (lsilogic / sas). I haven't tried to power it on, i would like to take a snaphost first. When i try to do that however, i get a "Could not create the differencing medium storage unit" error, with VERR_INVALID_PARAMETER in parenthesis.

1. Is what i'm trying to do supported in vbox?
2. Is it necessary to install "guest additions" before trying to take a snapshot?

[scottgus1]

2. GAs are not necessary for taking snapshots.

1. I'm relatively certain that vmdk's can be snapshotted, though I am not a heavy snapshot user. I have listened to experienced forum gurus who have warned against using snapshots for many reasons.

Snapshots make a guest more delicate and do not work as backups. They are similar to Windows' System Restore points: they are point-in-past-time markers, not extractable, useless without the base system in place, but easier to corrupt because the files are accessible on the host drive. They do not store "files", like a backup folder would. Virtualbox snapshots store changed disk sectors, which may or may not contain the entire file. They should only be used on guests you're experimenting with and with data you wouldn't mind losing. (The forums are replete with users destroying their important data because they did something wrong with a snapshot.)

Additionally, each snapshot, if used long enough, has the potential to grow to the final size of the original drive, and will not shrink once another snapshot is taken. The guest's total data size on the host could be many times what it would have been without the snapshots, and with tremendous amounts of dead data that will never be used or changed.

The best backup is a simple folder-copy of the guest folder after the guest is shut down. See this tutorial Moving a VM and re-interpret it as "Backing Up a VM".

As to why you're getting this result, I don't know. If you just copy the disk to a backup media or three, you can easily restore it to the first state by copying it back.

FWIW, if you copy the exact text of the error message (Maybe there's a "Copy" button that puts the text on the clipboard?) we may be able to help further if you really want to slide down the slippery slope of snapshots.

[NA!]

The best backup is a simple folder-copy of the guest folder after the guest is shut down.

Thanks for your input. I had some issues with snapshots and vbox in the past, so i'm not very fond of them either (in vbox at least, with esxi i have faced a problem just once and that was years ago).

Basically i'm trying to avoid copying around 80gbs of data just to do some tests. It seems that at the end, i will not avoid this.

Thanks again.

[NA!]

FWIW, if you copy the exact text of the error message (Maybe there's a "Copy" button that puts the text on the clipboard?) we may be able to help further if you really want to slide down the slippery slope of snapshots.

Failed to create a snapshot of the virtual machine DC03.

Could not create the differencing medium storage unit 'Z:\DC03\Snapshots\{4af9ac20-40f0-4416-8e3c-cfbffd29e050}.vmdk' (VERR_INVALID_PARAMETER).

Result Code: VBOX_E_FILE_ERROR (0x80BB0004)
Component: MediumWrap
Interface: IMedium {4afe423b-43e0-e9d0-82e8-ceb307940dda}