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bluecollarit
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What are the plusses of Growable disks over not preallocated disks

I just converted a virtual disk to growable and it took more space on the actual disk. Are there hidden advantages to growable disks.

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oreeh
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Growable disks (especially the monolithicSparse) have some disadvantages.

There seems to be a bug in Server and Workstation which prevents moving the VM to other places.

Since the monolithicSparse disks don't use an external disk descriptor file it is hard to repair this.

Another drawback of growable versus preallocated is the performance.

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pdrace
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I just converted a virtual disk to growable and it

took more space on the actual disk.

Took more space than what?

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bluecollarit
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the original file which resides on the host disk was 10mb after the conversion the new file was 470mb. The original file had a size limit of 50gb but it was not preallocated and only 10mb of space was being used for it. What it leads me to is that a growable disk doesnt necessarily save space.

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pdrace
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As far as I know there shouldn't be any difference in actual space used between size on a preallocated disk and a growable disk.

Are you looking at the space through virtual center or at the command line?

I use growable disks when it's not clear how much space is actually needed as this allows me to overcommit my SAN storage knowing that most users ask for far more space then they ever really will use.

As an example I have a VM that currently has 240 GB of growable disk allocated. It's actual usage is 70 GB. In virtual center it's capacity is 240 GB and used is 70GB.

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pdrace

bluecollarit
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This particular disk was not preallocated so it had a limit of 50 GB but in reality only took up 10 mb in a single file on my actual hard disk. When i converted it to growable it now takes up 470 mb of space. Since the single file on my hardisk is not preallocated and only takes the space it uses up to th 50 gb limit i dont see any real reason to use growable disks. And in the case of a small disk less than 470 mb it is actually detrimental. Tho 470 mb is not a big deal in todays environment. Are there any real virtues of using growable disks?

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bluecollarit
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I just rechecked the original sizes on files in my source folder and the size is about 470mb. so the disparity is not what i thought. my bad. I am still a little confused about the value of a growable disk since it doesnt really buy you space over a non preallocated. It just looks like it does through vmware server.

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oreeh
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Growable disks (especially the monolithicSparse) have some disadvantages.

There seems to be a bug in Server and Workstation which prevents moving the VM to other places.

Since the monolithicSparse disks don't use an external disk descriptor file it is hard to repair this.

Another drawback of growable versus preallocated is the performance.

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