What is the difference between VolumeMangager getPhysicalVolumes()[0].Open() and getLogicalVolumes()[0].Open()

Jan 27, 2010 at 11:57 AM

Hey,

I just want to understand the difference between a logical Volume and a physical Volume Stream.
Both are streams of the content of one partition, right?

Ciao Ephraim

Coordinator
Jan 27, 2010 at 9:22 PM

For most disk, you're right - the logical and physical volumes are the same.  The difference arises when you have one or more partitions using LDM.  With LDM, you can strip/mirror/span partitions across multiple disks.

With LDM disks, the logical volumes represent the storage as you'd see it in Windows (with a single logical volume able to span multiple disks), the physical volumes always represents the BIOS / GPT structure on the disk.

Cheers,

Ken

Jan 28, 2010 at 8:13 AM

Thanks for the explaination. I just wondered what its about. I didn't knew the LDM thing.

And in NTFSDump was a part which made the confusion complete:

 

            else if (Partition >= 0)
            {
                partitionStream = volMgr.GetPhysicalVolumes()[Partition].Open();
            }
            else
            {
                partitionStream = volMgr.GetLogicalVolumes()[0].Open();
            }


As I saw this, I was just "why the ... is here use logical for partition 0 and for any other partition or 0 too the physical !?! :)

Ciao Ephraim