2016-10-18, 07:33:13
Hello,
While Time Machine is great for many scenarios, VMs are not a very fitting scenario. Why? Well there's a long explanation, which I will try to write out soon, but the short story on your solution is that it will work until your backup space runs out. At that moment the promise is that Time Machine will start by deleting the oldest first. Yes it does that, except when it doesn't.
VM files are big and Time Machine has a tendency to drop bigger files earlier. Here is a post of a recent victim on that in the VMware Fusion forum:
https://communities.vmware.com/thread/544749
Another more obvious issue is that it is easy to forget to make timely backups this way.
Slightly less obvious is that you have to know very well what you are doing, like forgetting to shutdown will get you a backup with corrupted disks or like making a backup on a disk with running VMs that then ends up corrupting the running VM because of running out of disk space.
The goal of Vimalin is to help customers to create more reliable backups without having to be an expert.
Oh yes certainly. I might not have explained myself well. The problem is that if you zip the files outside of Vimalin that when you navigate over the backup archive, the files will be missing. So Vimalin will report your backup as broken as it does a quick list of files when you navigate in the backup archive screen. If you want to restore then you would have to unzip first.
If you agree that it is OK not to have a user interface for handling this part (except perhaps a checkbox to enable/disable the functionality) then I have a few ideas on how to implement this best. For details on this I think it is best if we discuss this via email. I will contact you later today on this.
FWIW in most programming languages building the GUI is what takes a lot of time, more as one would realistically expect, it is also the area that tends to get most bugs.
thanks,
--
Wil
Quote:Backups are easy - I shut them down, compress them, and move the compressed file to a "virtual machines backups" folder. The virtual machines folder is excluded from Time Machine, but the virtual machines backup folder is not, so the backups get copied to Time Machine.Yes I read your approach on this before, it can work. There are a few problems that I see with this however.
While Time Machine is great for many scenarios, VMs are not a very fitting scenario. Why? Well there's a long explanation, which I will try to write out soon, but the short story on your solution is that it will work until your backup space runs out. At that moment the promise is that Time Machine will start by deleting the oldest first. Yes it does that, except when it doesn't.
VM files are big and Time Machine has a tendency to drop bigger files earlier. Here is a post of a recent victim on that in the VMware Fusion forum:
https://communities.vmware.com/thread/544749
Another more obvious issue is that it is easy to forget to make timely backups this way.
Slightly less obvious is that you have to know very well what you are doing, like forgetting to shutdown will get you a backup with corrupted disks or like making a backup on a disk with running VMs that then ends up corrupting the running VM because of running out of disk space.
The goal of Vimalin is to help customers to create more reliable backups without having to be an expert.
Quote:* I trust Apple's Compress to ZIP feature in Finder. I ran tests with diff, and found that the results of uncompressing the ZIP are identical to the original.
-> This implies that the Vimalin MD5 file should still be valid after a Compress and uncompress cycle.
Oh yes certainly. I might not have explained myself well. The problem is that if you zip the files outside of Vimalin that when you navigate over the backup archive, the files will be missing. So Vimalin will report your backup as broken as it does a quick list of files when you navigate in the backup archive screen. If you want to restore then you would have to unzip first.
Quote:What Vimalin could potentially do for me:I've scripted myself a similar solution on VMware vSphere with some of my server VMs on there so understand where you are coming from. This is typically a need at Virtual Machine level. In other words, I am considering to add a checkbox in the "Select Virtual Machine" screen where you can decide to have that machine shut down gracefully for EVERY backup and then automatically restore it back to the power state it had before the backup.
* Save me from having to wake up every Sunday morning and:
* Shutdown the server at a known time every Sunday.
* Make the full copy.
* Restart the server.
* Delete old copies to prevent disk overflow.
Quote:I realize that most of the above would best be done with a user-written shell script that could be launched when the Vimalin backup completes.I always figured that people who script their backup wouldn't be helped by Vimalin. How wrong could I be?
If you agree that it is OK not to have a user interface for handling this part (except perhaps a checkbox to enable/disable the functionality) then I have a few ideas on how to implement this best. For details on this I think it is best if we discuss this via email. I will contact you later today on this.
Quote:-> May I suggest that you look at the Carbon Copy Cloner application to see an example of how Vimalin could work? Carbon Copy Cloner is a mature Mac application with many helpful features. It would serve as a good model for Vimalin.LOL, I will have a look at it, but for the moment I admit that my focus is on "getting things done" and redesigning the user interface certainly does not fit in that picture. The developer in me wants to rip it all down and rebuild in Swift, the realist in me knows that it would take a long time until I would be satisfied. Luckily the core of the system is in the worker process that handles the backup so I would certainly expect improvements in the user interface (GUI) over time, but it usually takes longer to get to that as expected.
FWIW in most programming languages building the GUI is what takes a lot of time, more as one would realistically expect, it is also the area that tends to get most bugs.
thanks,
--
Wil