Virtual Disk Drive Download

[Danny Hosford]

Wehave a VM on hyper-v the virtual hard disk located on drive E: We need to extend the virtual disk size but there is no free space available on drive E: I am thinking about easiest and safest option to resolve this issue. One way I am thinking to add more hard disk on this server and create a new drive F: to move the VM virtual disk to new drive using Move option. Once virtual disk move done then extend the virtual hard disk size. The operating system of both Host and VM is Windows Server 2012 R2.

Virtual disks and virtual drives are common components of virtual machines in hardware virtualization, but they are also widely used for various purposes unrelated to virtualization, such as for the creation of logical disks,software development, testing environments, and data management. They offer flexibility, ease of management, and the ability to simulate different storage environments without needing physical hardware.

A virtual drive is a software component that emulates an actual disk drive, such as an optical disc drive, a floppy disk drive, or a hard disk drive. To other programs, a virtual drive looks and behaves like an actual physical device.

In hardware virtualization, virtual machines implement virtual drives as part of their efforts to emulate the behavior of an actual machine. As with an ordinary computer, a virtual machine needs one virtual drive and one disk image to start up, except when it is performing a network boot. More virtual drives are added as needed.

Virtual optical drives are used on physical computers to transfer the contents of the optical disks onto hard disk drives. Doing so helps in resolving the problem of the short life span of CDs and DVDs and takes advantage of the faster data transfer rate of hard disk drives. However, virtual optical drives are also used for software piracy: early computer games used disc existence verification to ensure licensed use, which can be circumvented using virtual optical drives. As a countermeasure, the StarForce copy protection scheme attempts to thwart disc virtualization. Modern video games have migrated to online product activation as part of their distribution process.

I have concluded that there is not a way, after the fact, to tell what drive letter is pointing to what VHD file. I am hoping that the naming convention of the person who created this server is consistent with the drives listed in the virtual servers settings. It will pretty much be trail and error if it is not.

Based on the fact that VD3 is a Raid 5 array that is offline, the two disks likely belong to this virtual disk. You need to reassign the physical disks to the VD3 virtual disk. It may or may not recover the data on the raid set.

Adding the drives back to the VD3, can be done without shutting the server down. You will need to watch the status of the RAID 5. When it is back online, you can check status of the drive in the OS and determine if you need to restore or not.

You can try rewriting the VD configuration to those affected disks via creating a RAID5 array with exactly the same settings as before, using all the same disks, and skipping the initialization. That may work or may not, but if you cleaned the configuration, that is your only option to try before starting to mess with backups.

With Disk Management you can create, attach, and detach virtual hard disks. Virtual hard disks (VHDs) are disk image file formats that have similar functionalities to a physical hard drive and are designed primarily for use with Hyper-V virtual machines.

VHDs appear just like physical disks in Disk Management. When a VHD has been attached and made available to the system for use, it appears blue. If the disk is detached and made unavailable, its icon reverts to gray.

I've recently taken to converting a couple of mirrored RAID1 arrays into one large storage pool. I have two 2TB disks and two 3TB disks, altogether 10TB, which when mirrored should give me 5TB of usable space.

I started the storage pool with the two 2TB disks and one of the two 3TB disks, using the final 3TB disk as a backup of the old data to move to the new pooled storage. I set up the virtual disk as "mirrored" on top of the new pool, and had a little under 3TB of usable space.

After moving the backup from the extra 3TB drive to the new pool, I cleaned it, and added it to the pool. However, I'm now unable to extend the mirrored virtual disk to take advantage of the added space.

Unfortunately I cannot post images due to my starter reputation, but my pool shows up with 9.09TB capacity, and 2.64TB of free space. When attempting to extend the virtual disk, the maximum size allowed is 3.22 TB, only just a hair more then before I added the 3TB drive. Physical disks show that almost none of the new disk is being used, while the rest are full.

I ran into the same issue. Neograph's comment is irrelevant in this case, he's talking about traditional Windows Server disk mirroring, not Storage Spaces. Thin provisioning is also quite irrelevant in this case. You can use it as a workaround, but I think more cautious planning will be better both budget- and performance-wise, just read on and you'll see.

After quite some time spent on reading and playing around in Server Manager, I think I figured out what's going on. The thing is, SS has this thing called "columns". That defines how many disks data is striped across. If your virtual disk was created with 4 columns, data is only spread across 4 disks with Simple layout (i.e. RAID0) or 8 disks with Two-way mirror (i.e. RAID10), not all of them. Now this may be confusing for someone who comes from traditional HW RAID (like me), but that's the way it is.

So anyway, column size also defines how you can extend a virtual disk. Clearly, if your current VD has groups of 4 disks (= column size is 4), you can't add a "half" group by adding 2 new disks. So the number of disks required for expansion is basically

From what I understand, the default column size for a VD is the number of disks divided by copy count, but 8 at maximum, e.g. if you have 10 disks in a two-way mirror, column size will be 5, if you have 16 disks, column size will be 8, but if you have 24 disks, column size will still be 8 - by default. Note: you can check these numbers under VD properties (NumberOfColumns and NumberOfDataCopies properties undes Details).

Now you may wonder why would anyone use anything bigger than 1 for column size. The answer is of course performance. The bigger the column size the better the performance you get. Actually, it can be quite dramatic, here's a benchmark with column size 1 and 6:

I can't downvote by now, but I want to outline, that the basic information given in bviktors post is wrong - he is still thinking in Raid by saying you can't extend with half a diskgroup:

Consider a 2 Column 2 Copy Disk - It requires a minimum of 4 disks. If you loose one Disk, you could still access your data - but you cannot write anything anymore, cause you don't have 4 columns left where data could be stored!

Consider you would have added 5 Disks to that pool (which will be used based on Size by the Storage Spaces Subsystem, filled up in the best possible way to make all disks hit 100% at the same time) - loosing one Disk still retains your data - and keeps your Pool working for new writes, because you still have the minimum of 4 Columns left.

(You can use the same commands to retire "functional" disks and move data to other disks - this will allow some sort of redistributing the data, once you add a disk - but at the end you will always have one disk "empty". However in your case it would not work, due to the small number of disks. In 10 disk pool for instance, you could free up a 2 TB Disk, by distributing as little as 200 MB to every other disk. Re-Running the operation will now write prefered to the empty disk. Storage Spaces basically always says: "I have to write: 8 Blocks (NumberOfColumns * NumberOfDataCopies) with a size of 64 KB (Interleave / Number of Columns) each - give me 8 distinct disks out of the 10 disks with the least percentual usage, so I can throw the data there!")

Now, remember you got a mirrored virtual disk there: If you are going to extend that disk, Storage Spaces needs two have at least 1MB on two Disks, to extend the virtual disk by 1MB

I need to get my computer to treat an ISO image as if it's a physical optical drive. I've tried mounting it via loop devices, which is very useful, but it's not enough (basically, I need programs to be able to find it as a device, not a mounted filesystem). Any ideas?

I want programs to see it as if it is a actual, physical disk drive like /dev/cdrom, not a filesystem under /mnt or /media (for programs that automatically look for such drives but don't let me specify them manually). Cheesebaron's instructions are interesting and might be useful for something else (I may use it to test ext4), but not exactly what I'm looking for. I found similar programs that are available for windows (daemon tools and alcohol 120% came up in google searches), but it seems like this feature should be built in to linux (like nearly every other feature of those programs).

Can I ask, what is the benefit of this? As far as I know they are treated the same. The /media/cdrom is created from the /dev/ entry. When mounting an ISO you are just cutting out the need for the /dev/ entry yet for some reason you want it there. Why?

I'm looking at trying a project for class and as part of it I will need to create a "disk" to allow users to write some files (e.g. a RAM disk). I've used various languages, but I'm most familiar with Java (I could maybe use C# and get it done in time). I'm wondering what is out there that can do this.

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