Syncing Virtual Machine images, best practices?

[Raccoon]

I'm sure a lot of people are using it for that already. Since VirtualBox images are known to just die after few moves I would appreciate if people with experience share their knowledge.

How do you go about syncing your virtual machines?

For example, do you sync the live image you use, or just copy it in a synced folder when needed?

Do you keep them in TrueCrypt containers for example, for the fixed file size and partial sync or just throw in the image files?

Does Sync manage to sync just the changed stuff of an image file or always re-transfers the whole thing?

[Destigo]

I've been wondering the same. I will eventually be syncing some VMDKs as part of my disaster recovery plan. It would make sense that a sync only completes when the checksums of all files match across all clients. I have not yet encountered an issue where BitTorrent Sync corrupted larger files by syncing incomplete versions, but I have to assume that there are contingencies in place to prevent this from happening.

As a best practice, I would definitely avoid syncing a VM while it's running.

[fukawi2]

As a best practice, I would definitely avoid syncing a VM while it's running.

I don't think this should be a problem; AFAIK btsync won't sync an open file (which the disk image would be open while the VM is running).

The problem would be if you run the same VM in 2 locations, you then have the same original file "forking" into 2 versions. In theory btsync will overwrite the "older" one with the "newer" one, but you're probably asking for trouble.

[goli]

Hey there.

What's the thing with VirtualBox images? Are there any further details about what gets corrupt and why?

I would expect btsync to synchronize "bitwise". Even if there's a block based delta mechanism, the file content and naming of source and target should be 100% identically.

There's only one thing that might be different, that's privileges.

I don't know what's going to happen with files that are read-write-open by any process but some kind of "hidden". I don't know if there is such a thing, but maybe a process running as root can open a file handle without triggering a lock on it. That would be, imho, the only real scenario where btsync could create corrupt syncs. Assuming that btsync isn't corrupt in some way internally, of course.

So, I would go for creating a local backup folder. Just copy the your VirtualBox images to that backup destination and after that use btsync to synchronize onsite and offsite backup destinations.

There's software out that that does exactly that: Create backups of your VMs to e.g. NAS and ontop of that introduce versioning to them.

That's the way I am thinking about. Not for VirtualBox but for VMware ESX. I have a single ESX with local 4 disks RAID10 SSDs. The VMs get copied every night to a 3 disks RAID5 SATA-HDD NFS backup storage. That's the current thing, no btsync involved. My plan is to set up another 3 disks RAID5 SATA HDD NFS on another location and allow btsync to copy the data. But btsync should never deal with live source VMDK files.

Regards,

Stephan.