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Storage Virtualization 

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PCQ Bureau
New Update

Computer systems these days have at least 40 to 80 GB of hard disk space. In an ordinary organization, the consumption of the hard drive space may not be more than 50%, if you factor out the storage of personal data by users. This means that there’s lots of wasted hard drive space lying on the desktop nodes on your network, which is in GBs. The hard drive on a file server on the other hand, is usually hard pressed for storage space. How many times has the system administrator come up to you or sent you a message to clean your home directory on the server because it’s taking up too much space? Put the two scenarios together and you have a very interesting concept in hand–storage virtualization. Aggregate all this available disk space and put it under a single network share root. In this article, we’ll talk about how it can be done. 

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vSERV is a file system level aggregation software for Win 2000, which can be used like MS-DFS, but has some extra features

What you need



You basically need a software that can consolidate all the free storage on your network. There’s commercial software like vNAS/vSERV from 1vison. There’s also Microsoft’s Distributed File System or DFS, which is a part of Win 2000 Server. Let’s look at both options. 

vSERV from 1vison 



vSERV is a file system level aggregation software for Win 2000, which can be used like MS-DFS but has some extra features. At first glance, it looks like the DFS, but the differences are apparent when you start working on it. One major difference is that in DFS, the shared links to your DFS root physically exist in some computer system on your network. So when you try to copy data on one of them, it will only allow you to save as much data as is available on the physical drive on that system. This means that in DFS, the disk space will vary from folder to folder. In vSERV on the other hand, the disk space is constant, regardless of the actual size of physical disks. A limitation of vSERV on the other hand, is that it doesn’t have any fault tolerance mechanism out of the box. So if you delete a directory that the software had included in its storage pool, it won’t be able to stop this from happening. You’ll have to rely on your Windows 2000 network setup to control this. 

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Setting up vSERV



Being a commercial package, you can get a 14-days trial version of the same from

https://secure.1vision.com/products/buykey.cgi/vserv/try. Installation is very simple and you’ll need to run it on all the machines whose storage you’d like to aggregate. After the installation and restart, run vServ on each machine to open a configuration dialogue box. 

Here select the drive or folder (they just be formatted using NTFS), which you want to add to the aggregated share at the bottom of the dialogue box and select the check box “Enable

vSERV”. 

Now from any machine, click the Configure vSERV tab from the same dialogue box. Enter a group name and share name by just filling them into the first and second text box, and click on ‘Create Group’ button. You will find all the shares you have created on all the machines having vSERV installed, under the ‘All available servers’ column. Select them one by one and click on the ‘Add’ button, and your aggregated share is ready to serve. This aggregated drive will be present as a removable media under My Computer.

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The software is available in two versions, one is the economical version, namely eSERV/LX, which costs around $500, and lets you aggregate up to 280 GB of hard drive space. Another version that lets you aggregate unlimited space costs around $1200. A third product is also available that can aggregate NAS boxes into a virtualized storage. It’s called vNAS and a trial version of the same is also downloadable from their Web site. 

While the virtualized storage is easily accessible and works very well, it has its share of problems as well. Imagine the administrator shares an empty or less packed drive of a user’s machine into the virtual storage. This user has full read/write access to this storage space. Over time, this storage space fills up. What if one fine day, the user decides to delete this directory to free up some space on the machine? All the data, which might have been stored by other users on the network will be lost. 

The solution to the problem is to set proper policies on the network, which will prevent users from removing the virtualized storage space on their local machines. This is possible only if all computers are a part of the Windows 2000 network, and you set the right permissions to these directories. To do so, first right click on the virtualized partition/directory and go to the security tab. Here, add the user’s group by clicking on the Add button and selecting the group. Then remove the ‘full control’ and ‘Read and Execute’ access from the user group. 

Microsoft DFS



If you already have a Win 2000 server network and you don’t want to spend extra for creating this virtualized storage space, then you could use the DFS option. The good thing about it is in-built fault tolerance and replication. The bad thing is that it won’t show all your shared directories/partitions as one storage pool. Instead, it will show them all as different folder shares kept under one folder. Users then access this shared folder, and then use whichever folder they’ve been given access to. We talked about how you can setup DFS last year in Feb, but you can still find the article online on

pcquest.com.

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