KVM and Back Ups

matteo nunziati

@dustinb3403 I've been using this script in production for somethin glike 1 year when I was using KVM as hypervisor.
this is the facto the only good solution for KVM. It also supports gluster volumes!
you do nopt need to bring the VM down IF you build your VM disk on some snapshottable stuff like LVM or qcow (not sure about the latter).

I've written a small note for my usage at the time... need a bit to translate it in english. this is how I used it in brief

wget http://repo.firewall-services.com/misc/virt/virt-backup.pl
chmod 755 virt-backup.pl
yum install perl perl-XML-Simple perl-Sys-Virt
mkdir -p /var/lib/libvirt/backup
#(maybe you want this to be a share mounted from a remote NAS)
/$PATH/$TO/virt-backup.pl --action=dump --vm=VM_NAME --compress=pbzip2

note that I installed bbzip from EPEL to speedup compression and make full use of all server cores: my backups were scheduled during not working hours with the server idling for the most.

matteo nunziati

@DustinB3403 almost forgotten... I've this stub on github

Emad R

@dustinb3403

In my previous experiments which worked but have not used it in production. I would just freeze the VM, then rsync it, then thaw it. If your backing up to LAN down time will be very minimal and with rsync you can backup incrementally of you wish.

It is recommended to also stop services first then freeze then rsync then thaw then start services again. I liked it and its KISS principle.

Obsolesce

I found this. I may try it on my laptop later.

Live backup of QEMU/KVM/libVirt virtual machines via Duplicity
https://itefix.net/content/live-backup-qemu-kvm-libvirt-virtual-machines-duplicity

Obsolesce

Here's something as well... KVM live backup software, that's actually current:

https://www.handybackup.net/kvm-backup.shtml

JaredBusch

I have found that there are many easy ways to get a backup of your VM.

What I have not found is something that can look at those snapshots that are made and backup incremental differences.

I cannot offsite 1+ TB per day in image files.

Obsolesce

@tim_g said in KVM and Back Ups:

Here's something as well... KVM live backup software, that's actually current:

https://www.handybackup.net/kvm-backup.shtml

Wtf... the download is an EXE. I don't get it...

Obsolesce

@jaredbusch said in KVM and Back Ups:

I have found that there are many easy ways to get a backup of your VM.

What I have not found is something that can look at those snapshots that are made and backup incremental differences.

I cannot offsite 1+ TB per day in image files.

Yeah that would be great to find something like that. I'm looking. I remember someone finding something that's paid. But I forget what it was. I forgot to bookmark it.

JaredBusch

@tim_g said in KVM and Back Ups:

@jaredbusch said in KVM and Back Ups:

I have found that there are many easy ways to get a backup of your VM.

What I have not found is something that can look at those snapshots that are made and backup incremental differences.

I cannot offsite 1+ TB per day in image files.

Yeah that would be great to find something like that. I'm looking. I remember someone finding something that's paid. But I forget what it was. I forgot to bookmark it.

I pay for that functionality now with Hyper-V and Veeam. So I do not mind paying for it for KVM.

Obsolesce

Found it:

https://storware.eu/en/storware-vprotect/

It shows incrementals in the screenshots anyways.

stacksofplates

You could theoretically just use one of the scripts to do incremental. It’s all AOW/ROW so you just get a new disk each snapshot. Then at the end of the week or whatever block commit everything back into the main image and start over.

JaredBusch

@stacksofplates said in KVM and Back Ups:

You could theoretically just use one of the scripts to do incremental. It’s all AOW/ROW so you just get a new disk each snapshot. Then at the end of the week or whatever block commit everything back into the main image and start over.

Something like that is what I want. Replicating what I get from Veeam now.

dave_c

Another option: http://convirture.com/solutions_backup.php

Obsolesce

Okay, so after doing some research, I've found some excellent news regarding KVM and incremental backups. But it also comes with some bad news.

It looks like the ability and support to do incremental backups is fully integrated into QEMU (I think as of 2.5).

It uses what I keep seeing referred to as Bitmaps, or more specifically Dirty Bitmaps or Block Dirty Bitmaps.

The bad news, from the little research I've done so far, is that all this stuff is managed using JSON files, which would be done via the QMP (QEMU Machine Protocol). This basically tells me that the only way to do incremental backups with KVM, is if you are a software engineer and know how to build software that uses the QMP, or have the time to figure it all the hell out. It all seems relatively simple...

So, this means we're still stick using something that costs money... because I doubt anyone would build something like this open sourced when there's a lot of money to be made... unless Google or someone does it for internal use and decides to make it open source.

I spent some more time looking at things since writing everything above, and looks like you can get starting issuing QMP commands via telnet to start, and then by CLI after installing socat and rlwrap. Again, no idea what I'm looking here: https://wiki.qemu.org/Documentation/QMP, but perhaps this deserves some more looking into.

Maybe someone else can clear it up for me so I know what I'm looking at. I wish I had more time and programming skills... I'd definitely be into figuring this stuff out and putting it out there.

maybe SodiumSuite devs feel like being nice?

Anyways, here are my references:

https://kashyapc.fedorapeople.org/QEMU-Docs/_build/html/docs/bitmaps.html

https://wiki.qemu.org/Features/IncrementalBackup

https://www.linux-kvm.org/images/e/e6/Kvm-forum2017_backup.pdf

https://events.static.linuxfound.org/sites/events/files/slides/kvm2015_rh_light_44_vfinal.pdf

https://wiki.qemu.org/Documentation/QMP

stacksofplates

@tim_g
One problem is the dirty bitmapping in the API is push only so anything expecting an interactive API won't work. This means the backup system can't query the API for dirty bitmaps, only create them.

(At least it was this way the last time I looked at it)

AdamF

This is quite an old thread, but it discusses exactly what I am researching.

I use KVM (via Fedora) in my home lab, and currently, since I have no production workloads on it, I run file only backups via a couple scripts.

However, I'd like to explore the possibility of using KVM in a production scenario. Backups are obviously key here. Automated, live, nightly snapshots (entire VM) is what I am looking for.

What would be the best way to achieve this? Assuming I am running a single KVM server with local storage.

Is this still a good option: https://storware.eu/products/vprotect/

Is there something better?

Can something like ProxMox handle this? https://www.proxmox.com/en/proxmox-ve

black3dynamite

Proxmox backups are always a full backup.
https://pve.proxmox.com/wiki/Backup_and_Restore

scottalanmiller

@fuznutz04 said in KVM and Back Ups:

However, I'd like to explore the possibility of using KVM in a production scenario. Backups are obviously key here. Automated, live, nightly snapshots (entire VM) is what I am looking for.
What would be the best way to achieve this? Assuming I am running a single KVM server with local storage.

You come back to the fundamental question of... why are you approaching backups this way?

Backups have never been something that we think of at the hypervisor level for decades, all of a sudden its the hot new "everyone has to do it" way. But it has all kinds of limitations and should only be a consideration for certain workloads, and only one of the options. Backups are always by workload, never by platform. It's fundamentally a flawed way to think of backups because it hides the scope and complexity of getting reliable backups and causes all kinds of problems.

Under no circumstances can anyone answer how you should take backups based on knowing your platform - no matter what hypervisor or OS you use, your backups have to be a decision based on your workloads.

AdamF

@black3dynamite said in KVM and Back Ups:

Proxmox backups are always a full backup.
https://pve.proxmox.com/wiki/Backup_and_Restore

Do you use or have any experience using proxmox? Does/can it just run as a VM on the host?

scottalanmiller

@fuznutz04 said in KVM and Back Ups:

@black3dynamite said in KVM and Back Ups:

Proxmox backups are always a full backup.
https://pve.proxmox.com/wiki/Backup_and_Restore

Do you use or have any experience using proxmox? Does/can it just run as a VM on the host?

PM doesn't do anything special, you still need to deal with the backups on a workload basis.