Backup Solution for Cluster

[aarb000]

I just installed a three node cluster using an iSCSi target. I have 1.8TB of local storage on each node. I used the default install settings so I have two LVMS on each system.

root 96 GB
data 1.49 TB

Since most of my VMs will be on iSCSi, I was hoping to backup to the local servers, but since it is LVM, I can't. What are my options to use the local storage?

I can think of a few ideas, just don't know what can be done safely or if any of these ideas would even work. I'm not in production, but don't want to setup everything again.

1. I would think I could either shrink or erase data and increase root. Then I could run some VMs locally on data, some on the cluster, and backup to root.

2. My iSCSi is a debian system. I have 4 LVMs that were installed during setup that are mounted to the file system. root, var, home, and tmp. I created a 5th one called iscsi and am using that as my target. Is it possible to also mount that LVM to the file system say at /mnt/scsi and then export that as NFS?

3. On the ProxMox system, /dev/mapper/pve-root is an LVM, yet is mapped to /. Is it possible to map the data lvm to say /mnt/data and then backup to that?

Ultimately I'd like to utilize all of that local storage to backup stuff on the cluster, and also it would be great to use the NAS to backup some of the VMs (systems with USB dongles) I need to run locally.

I'm open to other suggestions as well.

 

[aarb000]

Based on this thread, https://forum.proxmox.com/threads/local-lvm-storage-and-vm-format.27209/page-2, I think I want to delete pve/data, then create a non-thin pve/data and mount the file system so it works like the old default system did.

That way, I can run some VMs on the local file system, and backup VMs running on shared storage locally.

In addition, I could create snapshots on the local VMs. Are there any downsides to this approach?

 

[udo]

In addition, I could create snapshots on the local VMs. Are there any downsides to this approach?

Hi,
yes - on non thin lvm storage you can't create snapshots (with the pve-gui). You can create snaphosts with lvm on the cli, but this is normaly not that what you want.

But you can create an LV for backup, without destroying your pve-data if you have enough storage space.

I had such an config on an cluster years ago ( 100GB system on hw-raid1 with 2*3TB-disks, the remaining space are used for backup; VMs on faster raid-10).

Udo

 

[aarb000]

Thanks for the response.

I went ahead and removed the thin lvm 'data' and created a new data lvm and mounted it to the file system. I soon realized I was wrong about snapshots. Wanting snapshots, I created a qcow vm from a template and did some tests. I know it isn't scientific, but I copied a file to that VM at the exact same speed as when it was on a thin lvm. None of my VMs require much in the way of disk performance so I think qcow is acceptable.

I also removed iSCSI from the other Debian server and instead offered the space with NFS. I now can backup my locally run VMs to the NFS share, and I can backup the HA VMs running off of the NFS to local storage. This way all of my VMs are in two locations. I also have the ability to create snapshots on the NFS if I use qcow which should be helpful.

All in all, I think this solution will meet my needs.