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danielalpha
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Large amounts of AVHDX, MRT and RCT Files

Post by danielalpha » May 15, 2019 3:14 pm

Hello,
I am using B&R now a couple of weeks in my lab and i am very appreciated.

but i got a Problem: My VHD Disk is running out of space.

I have no Snapshots or similar in Hyper V, that files have to be created by veeam.

All VMs have .vhdx.mrt and rct files, but only one of the pair, One VM of mine ( The Filer VM ) has now about 80 GB of that files.

What did i misconfigure ? I configured the VM in my mind same as the others.

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Mike Resseler
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Re: Large amounts of AVHDX, MRT and RCT Files

Post by Mike Resseler » May 16, 2019 4:56 am

Hi Daniel,

First: Welcome to the forums
Second: Can you tell me exactly what that Filer VM has. the .VHDX file is a disk (so if that VM has multiple disks, you should see multiple). Per disk, you should see MRT and RCT files which is the change block tracking information. It remains attached to the disk.
When Veeam takes a backup, you should (during the backup) see a .AVHDX file which is the temporary snapshot. What files are you all seeing?

danielalpha
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Re: Large amounts of AVHDX, MRT and RCT Files

Post by danielalpha » May 17, 2019 7:40 am

Hello,
Thank you very much.
The Filer VM has 1 4 TB VHDx mounted which is stored at the Host. Additionally it has a VHDx for the System which is about 100 or 30 GB great.

I have about 80 GB of these MRT and RCT files. I have just 1 or 2 Restore Points configured. The Space is now such low, that i cant backup Any VM on that SSD anymore.

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danielalpha
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Re: Large amounts of AVHDX, MRT and RCT Files

Post by danielalpha » May 17, 2019 2:02 pm

Here a Screenshot: https://ibb.co/HNggyfh

The Problem is slowly getting serios for me. The whole System is gonna Crash when the Space is zero, i will have to shutdown B&R soon if the Problem doesnt gets fixed.

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danielalpha
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Re: Large amounts of AVHDX, MRT and RCT Files

Post by danielalpha » May 18, 2019 12:29 am

Thanks for the Tipp, but as I mentioned above, there are no snapshots or similar in hyper V created.

Mike Resseler
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Re: Large amounts of AVHDX, MRT and RCT Files

Post by Mike Resseler » May 18, 2019 5:12 am

Hey Daniel,

I'm afraid there is another problem which (at least I think) has nothing to do with Veeam. (PS: When we backup, we do the same thing, we take "snapshots"). Your RCT and MRT file are too large so I do think there is an issue there and you might need to contact Microsoft support for this. It seems that the change block tracking is going a bit crazy

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Re: Large amounts of AVHDX, MRT and RCT Files

Post by danielalpha » May 18, 2019 9:05 am

Hello,
Sadly Microsoft isn't giving support to students with a home lab.
I'm gonna move the VM today to another very slow storage and will try to figure out the problem.

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danielalpha
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Re: Large amounts of AVHDX, MRT and RCT Files

Post by danielalpha » May 18, 2019 1:32 pm

Is it a try worth, to make a Backup with Veeam Agent, then delete the old VHDx which is buggy and create a new vhdx and then restore the Backup to that ?

Mike Resseler
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Re: Large amounts of AVHDX, MRT and RCT Files

Post by Mike Resseler » May 19, 2019 4:57 am

That would be sure a possibility. You would threat it as a "physical box". Don't forget to create the recovery media ISO then so you can start the recovery from that ISO, will make your life much easier

danielalpha
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Re: Large amounts of AVHDX, MRT and RCT Files

Post by danielalpha » May 19, 2019 8:20 am

Good Morning,
i moved the VHDx now to a another Storage. As magic, Hyper V did start automatically the Merge Progress after the VHDx was moved.

At now the System is in a normal State, but i am now testing with Veeam B&R if the Problem will occur again.

As you said Veeam creates Snapshots like the Checkpoints from Hyper V, in my opinion it could be possible that the Mechanism that automatically merges this checkpoints could be buggy in my system ?

Thanks for your Help so far.

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Re: Large amounts of AVHDX, MRT and RCT Files

Post by danielalpha » May 21, 2019 8:17 am

Hello,
anyone got an idea? One of the 4 TB Drives is getting the Files again, i will have to migrate the Storage, but i dont have another 4 TB here :)
So it would be nice, if i could fix that problem without migrating the Store.
The System Disk seems to dont overflow again, the avhdx files there from veeam are deletet after backup successfully.

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Mike Resseler
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Re: Large amounts of AVHDX, MRT and RCT Files

Post by Mike Resseler » May 21, 2019 8:38 am

So If I understand it correctly. You have migrated the VM, you take backups with Veeam B&R and the AVHDX files are deleted after backup. At that point in time, how big are the MRT and RCT file? They should be smaller again

danielalpha
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Re: Large amounts of AVHDX, MRT and RCT Files

Post by danielalpha » May 23, 2019 5:50 am

Good Morning, thanks for your Reply.

So i try to explain it well:

I had the Problem VM-Wide, with the System VHDx (about 30 GB) and with the Storage VHDx (About 2 TB yet). In Hyper V were no Checkpoints as i could see. i Tried to merge with Powershell, but there was not even an Output, i think because Windows has no Checkpoints registered and so the Action was successfull quitted.

Then i had to move (Just the one) the System VHDx File to another Storage because the Flash Storage was almost full and then all the VMs and the Host would crash.

After Hyper V completet the move Action of the System VHDx successfully, it autmatically shows me that it began Merging. It took about 12 Hours to Merge all the SystemVHDx Files and the Files of the 2 TB VHDx. At that Point, everything was in a normal state again.

But when Veeam takes new backups, it creates new Files again, as it is normal, and it deletes now old Files in the SystemVHDx, but still not on the great Drive, with 2 TB.

I would now sayed i just move that Storage one time too, as Workaround for that problem, but i have no Storage at home where i could migrate it, and the Filer is always Busy too and has to be High Avaible. I will Check today if the Problem is surely Fixed with migrating the Storage one time, and if it is, i will buy a external Drive to migrate the Storage. Pretty much Work, but by the Way, Veeam B&R is awesome in Home Lab especially for Testing etc pp..

Sorry for my bad English.

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danielalpha
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Re: Large amounts of AVHDX, MRT and RCT Files

Post by danielalpha » May 24, 2019 2:56 pm

Is that normal ?

https://ibb.co/VM8pqw7

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