Local storage, suggestions?

[Alessandro 123]

I would like to try proxmox on a server with local storage and hardware raid.

What do you suggest? An LVM volume for each VM like Xen does?
A big filesystem with one qcow image for each vm?

I absolutely need the ability to export a running vm, for backup purposes, with no downtime. i don't need to snapshot the ram and vm state. Only disks and the ability to restore that dump somewhere.

Qcow seems the more flexible format but:
1. Putting all images is a filesystem would lead to fsck in case of unclean shutdown. Fsck could take many hours/days to run on a 2tb raid6 even with sas disks

2. Any inconsistencies found by fsck could lead to vm/data loss if the inconsistency is on the qcow file

3. I've read that qcow suffered corruption issues and having my production vm stored in a file that could corrupt is scaring me

Probably an lvm volume with raw disk osd the safest choose

What do you suggest?

 

[fireon]

We've used many year on a lot of Server qcow2. Any problem was in conjunction with an HW Raid issue. The only one really Problem was that when you do an snapshot with qcow2 and a lot of RAM in the VM, then you get sometimes an timeout, sometimes for creations and most on delet.

Since 4.2 default we use also LVMthin. Without problem. LVM exists a long time, and is absolutly stable. So yes use it. Backup without downtimes is a mainfeature with.

The third thing, also the ZFS way is absolutly stable, much more features, you can alos use it. But with an an real SAS/SATA controller no HW Raid. If would like to try this, please read about ZFS in forum. There are importand dependencies.

 

[Alessandro 123]

I don't know zfs and I'm not prone to put unknown software in production.

So are you suggesting local storage with lvmthin and raw disks across the volume? One volume for each vm right?

Any guide about this?
I'm not interest in thin provisoning, and i prefere to use stand provisioning. Less issues in case of out of space due to a wrong overCommit

With both lvm and lvmthin i'll be able to do exports/backup by snapshotting? Obviously this doesn't allow me to snapshot the ram content but I'm not interest in this

 

[fireon]

Ok, the default is thinlvm, not LVM so no you have Thinprovisioning as default on. When give the right space you never will running out ov space. But yes you can also use really only raw Images. Then you must delete the thinlvm storage, add an mormal LVM or only a ext filesystem. But be aware, no snapshots in this config available. So for the best i recommend to use thinlvm. It works fine and you have really all features, maybe you need they sometimes but it's up to you.
https://pve.proxmox.com/wiki/Storage_Model

 

[Alessandro 123]

Ok for thinlvm.
Also, the Live Snapshot (with RAM and VM state) would be available with thinlvm ?

But here: https://pve.proxmox.com/wiki/Storage_Model#LVM_Groups_with_Local_Backing is using LVM, not thinlvm

 

[fireon]

Ok for thinlvm.
Also, the Live Snapshot (with RAM and VM state) would be available with thinlvm ?

Yes.

But here: https://pve.proxmox.com/wiki/Storage_Model#LVM_Groups_with_Local_Backing is using LVM, not thinlvm

This was the old one, documentation not up to date.

 

[Alessandro 123]

Having an outdated documentation is bad
Do you have the updated link?

 

[fireon]

Having an outdated documentation is bad
Do you have the updated link?

No, but you can to it for us after your experience, which would greatly contribute to the community. But Thin Lvm is quite the same such lvm. The only one difference is thinprovisioning.
Google is your friend: http://www.tecmint.com/setup-thin-provisioning-volumes-in-lvm