Multi-attach disks and <inaccessible> machines
Posted: 9. Sep 2018, 04:58
I'm getting completely lost in what's called the Media Registry now. I have a fairly big setup and since i started moving machines across servers, sneaky problems started to appear. Everything is managed by vboxmanage on command line, so keep your click-throughs at bay.
I'm trying to patch a bigger picture here, so bear with me.
The media registry is supposed to keep tab on all the disks attached to all VMs, this enumeration is being serviced by the VBoxSVC daemon on linux.
Then there's that little habit of VirtualBox to keep the differencing children's media description in the .vbox file in which a base image has been initially attached to.
When i'm moving a VM with a differencing disk to another server, i detach the disk with vboxmanage storagectl and the re-attach it on the new server and it's fine(since there're other attachments already to the same base disk and it is in the VMR).
But when the server reboots, building the Media Registry fails as it can no longer locate the proper parent UUID for the differencing disk(it's in the registry at least once, but not in the particular .vbox file). The machine starts showing up as inaccessible. And what i basically do is unregister it,delete the <Image/> tag from the .vbox file , re-register it and re-attach the disk by filename.
1. Is there any degree of control upon how the media registry is being built(the GUI has a basic management for it, where at least you can re-scan)
2. Is the MR strictly hierarchical in terms of image resolution(as in does it just need to know where a Parent disk is, or it needs to see an explicit declaration that Child A starts from Parent A)?
3. Is there a lookup path as i can see it's trying to lookup from in-memory database and from parsing the .vbox files?
Please, ask questions in case this all reads non-sense.
I'm trying to patch a bigger picture here, so bear with me.
The media registry is supposed to keep tab on all the disks attached to all VMs, this enumeration is being serviced by the VBoxSVC daemon on linux.
Then there's that little habit of VirtualBox to keep the differencing children's media description in the .vbox file in which a base image has been initially attached to.
When i'm moving a VM with a differencing disk to another server, i detach the disk with vboxmanage storagectl and the re-attach it on the new server and it's fine(since there're other attachments already to the same base disk and it is in the VMR).
But when the server reboots, building the Media Registry fails as it can no longer locate the proper parent UUID for the differencing disk(it's in the registry at least once, but not in the particular .vbox file). The machine starts showing up as inaccessible. And what i basically do is unregister it,delete the <Image/> tag from the .vbox file , re-register it and re-attach the disk by filename.
1. Is there any degree of control upon how the media registry is being built(the GUI has a basic management for it, where at least you can re-scan)
2. Is the MR strictly hierarchical in terms of image resolution(as in does it just need to know where a Parent disk is, or it needs to see an explicit declaration that Child A starts from Parent A)?
3. Is there a lookup path as i can see it's trying to lookup from in-memory database and from parsing the .vbox files?
Please, ask questions in case this all reads non-sense.