Drivepool and VHD(X) files and “Other”.

[Bic]

Hi, running Drivepool and Scanner on Windows 2012R2 with 4 * 3TB drives. Added the disks to a pool and set for (2 *) duplication. There is currently no other data stored on any of the disks.

 

I was adding VHDX files to my Virtual Machines yesterday, storing them on the Drivepool drive, and noticed that as I was adding them the value of “Other” was going up under the Drivepool interface.

 

Looking in My Computer I have used about 0.4 TB of space on each of the disks, so in total 1.60TB of data.

 

Looking at the Pool disk in My computer shows I have about 1.59 TB of data on it (so those 2 figures just about match). Also a DIR /s *.* of the Drivepool drive shows a total of 812GB if data, so ½ of what’s shows above, so that all matches.

 

However looking in the Drivepool interface, I see that it says:

 

Duplicated 1.33TB Other 279GB (I have run Re-measure a few times to be sure) which in total equals 1.6TB.

 

I understand that “Other” includes non pooled data on the disk (which I have none of), and stuff such as metadata and “slack space”, but 279GB is quite a high figure, and quite close to the total size of the VHD(X) files on the Drivepool at about 234GB.

 

I think the VHD(X) files are however being duplicated, as I have a VMBackup folder with 4 VHDX files in it, and under the pool folder on E: & F: I can see 2 of the files on each of the disks, and under the pool folder on G:  & H: I can see the other 2 files.

 

So it seems they are being duplicated, but showing up in the interface as Other.

 

Any thoughts.

[Christopher (Drashna)]

Could you install this beta build?

http://dl.covecube.com/DrivePoolWindows/beta/download/StableBit.DrivePool_2.2.0.634_x64_BETA.exe

 

This should fix the specific issue you're seeing, actually (sparse file related)

[Bic]

So, I installed the above Beta, but still get the same issue.

 

After a reboot (with all my VM's stopped) it said that I have 102 GB of other, but I then remembered that I still had a VHDX file of about 56 GB "mounted" at the time to the host machine, so I dismounted it and ran re-measure and it then said I had 1.14 GB of other which would seem about right. I then re-mounted this VHDX file and also started up my VM's and then after another re-measure it said I had 288 GB of other. This is almost exactly double the size of all "in-use" VHDX files of 144 GB.

 

So, it seems that it doesn't like (or report correctly) the in-use VHDX files.

[Christopher (Drashna)]

Okay, it definitely sounds like it's not measuring the in use files properly.  

 

Could you enable file system logging, and remeasure the pool when one or more VMs are running?

http://wiki.covecube.com/StableBit_DrivePool_2.x_Log_Collection

[Bic]

Logs uploaded.

[Christopher (Drashna)]

Talking with Alex, this sounds like it may be normal, and not something we can easily "fix".

Specifically, this has to do with the VHDs, and how they're opened by HyperV and how they interact with the file system. 

 

Regardless, I've flagged the logs for Alex, to take a look at, just in case something else is going on or if it's something we can fix easily.

 

https://stablebit.com/Admin/IssueAnalysis/18755

[Bic]

Ok, thanks.

 

If it's "normal" then that's ok, as long as the files are being duplicated (and I think they are). I just noticed it, and thought I would raise it with you.

[Christopher (Drashna)]

Ok, thanks.

 

If it's "normal" then that's ok, as long as the files are being duplicated (and I think they are). I just noticed it, and thought I would raise it with you.

Yeah, it's an "in use" issue with measuring. The size isn't properly reported back to us, if the file is still locked (held open). 

 

And as long as you have real time duplication enabled (by default), then the contents are written in parallel to both destination drives.  This includes creation, modification, etc.  So yes, they should absolutely remain duplicated.