Sizing Server for Volume Shadow Copy

We're planning to migrate a couple of NetWare servers with a considerable amount of data to new Windows Server 2003 R2-based systems.

As we use Salvage regularly under NetWare, one of the features that we're planning to implement in the new environment is Volume Shadow Copy.  However, I don't have much experience of this feature and how I go about sizing it.

On each of the file servers we plan to create a dedicated partition (or disks) for shadow copy.  As a rule of thumb, what size does this need to be?  For instance, does it need to be identical to the data that is being copied, or 1.5 times as large, or 3 times as large?

Any advice, guidelines or useful links would be much appreciated.
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KCTSConnect With a Mentor Commented:
You CAN put the shadow copies on another volume. When you right click on the drive and select the Shadow Copies tab, there is a SETTINGS button. You can click this and specify were the shadow copies will be located. You can also set how much space to allocate (the min is 300mb) normal recommendation is 10-20% of data space. Once the shadow copy space is full older previous versions are overwritten.
Frank McCourryV.P. Holland Computers, Inc.Commented:
Shadow copy typically takes about 30% of the volume it is enabled on.  This is adjustable.  There is no provision for putting the shadow copies on another drive.  

Instead of looking at a dedicated drive for this purpose, you should be sizing the drives you will store data on at least 33% lager than your data.  Give yourself room to grow also.  Drives are cheap nowdays, so I would put in drives as large as I can get.

Fault tolerance (RAID) would be my concern, shadow copies are great, but if the drive fails, it won't help.  I would recommend setting up at least a mirror set (RAID0) or a Stripped Mirror Set (RAID10) as well as shadow copy.  A tape drive wouldn't hurt either.
StuFox100Connect With a Mentor Commented:
First thing first - you can place the shadows on different drives - under VSS use settings on the individual drive to locate the shadows on a different drive.

We use second drives where possible as we seem to get better performance writing the shadow to different spindles.

As for space - it depends on usage and changes to the content - VSS only hold 64 instances before it starts to recycle space. As a guide we have one file server which has lots of small files but many changes and we get away with about 20%. As for systems with bigger files  I would make the space more like 40% if you think they will change frequently.

howellajAuthor Commented:
Thanks for the advice: much appreciated.

I also found an excellent article on TechRepublic that covers VSS and gives some quite detailed sizing recommendations.

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