How PBS Live Restore will work in this case

[Remarkable-Guille]

Hi Guys,

Let's say I'm restoring a VM using the Live Restore features (excellent, by the way, and a very clever way to restore)

Inside the VM there is a file called important_data.txt

In the middle of the live restore, the user doesn't see the file (because it hasn't been restored yet) and creates a new one with the same name and in the same exact location)

My question is: At the end of the live restore, which version will be on the VM? the one stored in PBS or the new one created by the user?

I'm asking this because a few days ago, I did a live restore for a cPanel server; most of the users had their site up and running in about an hour (a real lifesaver), but the whole live restore process took live +10 hours.

The next day one customer complained that all day mail activity was gone, and sent and received mail disappeared. I'm trying to understand how it happened; I'm guessing that MDBOX files were created by the server and later overridden by the restoration process.

 

[UdoB]

In the middle of the live restore, the user doesn't see the file (because it hasn't been restored yet)

That's not the way it works.

When you list the files in a folder the blocks where that folder-information is stored get restored. Immediately, before the resulting listing is given back. So if there is a file called important_data.txt you (the OS) will know it.

 

[Lukas Wagner]

When you list the files in a folder the blocks where that folder-information is stored get restored. Immediately, before the resulting listing is given back. So if there is a file called important_data.txt you (the OS) will know it.

Exactly. The process should be completely transparent to the user - the only noticeable side-effect of live-restore is decreased performance if data is accessed the first time.

For more details, read through the "Live-Restore" section in the wiki [1].

[1] https://pve.proxmox.com/wiki/Backup_and_Restore

 

[Remarkable-Guille]

Make sense, Thank you