Mounting vdisk in read only while VM is running

[Guillaurent]

Hi there

 

I'm happily running an unRAID box for quite a while now with an Win10 VM attached to the monitor.

The Win10 VM has a 2TB vdisk mounted for user data "local" storage (Documents, Images...).

I would like to back the content of this vdisk to a remote site but uploading the 2TB img file every time is way too much, a simple rsync would be plenty enough.

 

Is it possible to mount (read only) the vdisk img file directly on the server (say in /mnt/temp/vdisk) while the VM is running in order to back the content up?

 

I wanted to give it a shot but I don't really want to mess the vdisk image...

[JonathanM]

I think it would be much simpler to set up a backup client in the VM, that way no conflicts with open files and stuff. I use the UrBackup container to successfully automatically back up several machines, both linux and windows.

[scorcho99]

Doesn't rsync do delta copies as an option? Are you concerned about downtime of the VM (it's shutdown while the giant file is copying) or the bandwidth needed?

 

vdisks can be mounted directly, I've done it with nbd and qcow2 disks anyway. I'm not sure about concurrent with a single read only. I want to say I've heard of that as something you can do with vware vdisks but it's only a vague memory.

 

For my backups I shutdown all my VMs and create a read only btrfs snapshot and then immediately start them backup. Then I backup from the snapshot. The VMs are only down for a few minutes and can change and run while the backup is slowly performed on a snapshot of them in an off state. Maybe something like that?