Is a "snapshot" backup an entire disk image copy?

[jaxjexjox]

I just woke up to a crashed virtual machine.

Thanks to some help on the internet I've run the command:
journalctl --since "2022-05-20 12:00:00" --until "2022-05-21 12:00:00"



Revealing the following:

May 21 00:14:55 proxmox kernel: pcieport 0000:00:1d.0: AER: Corrected error received: 0000:01:00.0
May 21 00:14:55 proxmox kernel: nvme 0000:01:00.0: PCIe Bus Error: severity=Corrected, type=Physical Layer, (Receiver ID)
May 21 00:14:55 proxmox kernel: nvme 0000:01:00.0:   device [1c5c:174a] error status/mask=00000001/00000000
May 21 00:14:55 proxmox kernel: nvme 0000:01:00.0:    [ 0] RxErr
May 21 00:15:15 proxmox pmxcfs[1313]: [database] crit: commit transaction failed: database or disk is full#010
May 21 00:15:15 proxmox rsyslogd[1006]: file '/var/log/syslog'[8] write error - see https://www.rsyslog.com/solving-rsyslog-write-errors/ for help OS error: No space left on device [v8.2102.0 try https://www.rsyslog.com/e/2027 ]
May 21 00:15:15 proxmox pmxcfs[1313]: [database] crit: rollback transaction failed: cannot rollback - no transaction is active#010
May 21 00:15:15 proxmox rsyslogd[1006]: action 'action-1-builtin:omfile' (module 'builtin:omfile') message lost, could not be processed. Check for additional error messages before this one. [v8.2102.0 try https://www.rsyslog.com/e/2027 ]
May 21 00:15:15 proxmox pvescheduler[821177]: unable to delete old temp file: Input/output error
May 21 00:15:15 proxmox rsyslogd[1006]: file '/var/log/daemon.log'[9] write error - see https://www.rsyslog.com/solving-rsyslog-write-errors/ for help OS error: No space left on device [v8.2102.0 try https://www.rsyslog.com/e/2027 ]
May 21 00:15:15 proxmox rsyslogd[1006]: action 'action-2-builtin:omfile' (module 'builtin:omfile') message lost, could not be processed. Check for additional error messages before this one. [v8.2102.0 try https://www.rsyslog.com/e/2027 ]
May 21 00:15:15 proxmox QEMU[8366]: kvm: terminating on signal 15 from pid 1010 (/usr/sbin/qmeventd)
May 21 00:15:15 proxmox rsyslogd[1006]: file '/var/log/daemon.log'[9] write error - see https://www.rsyslog.com/solving-rsyslog-write-errors/ for help OS error: No space left on device [v8.2102.0 try https://www.rsyslog.com/e/2027 ]
May 21 00:15:15 proxmox rsyslogd[1006]: action 'action-2-builtin:omfile' (module 'builtin:omfile') message lost, could not be processed. Check for additional error messages before this one. [v8.2102.0 try https://www.rsyslog.com/e/2027 ]
May 21 00:15:16 proxmox kernel:  zd0: p1 p2 p3
May 21 00:15:16 proxmox kernel: vmbr0: port 3(tap100i0) entered disabled state
May 21 00:15:16 proxmox qmeventd[1087523]: Starting cleanup for 100
May 21 00:15:16 proxmox qmeventd[1087523]: Finished cleanup for 100
May 21 00:15:15 proxmox systemd[1]: Stopping LVM event activation on device 230:3...
May 21 00:15:15 proxmox rsyslogd[1006]: file '/var/log/daemon.log'[9] write error - see https://www.rsyslog.com/solving-rsyslog-write-errors/ for help OS error: No space left on device [v8.2102.0 try https://www.rsyslog.com/e/2027 ]
May 21 00:15:16 proxmox lvm[1086073]:   pvscan[1086073] /dev/zd0p3 excluded by filters: device is rejected by filter config.
May 21 00:15:15 proxmox systemd[1]: Requested transaction contradicts existing jobs: Resource deadlock avoided
May 21 00:15:15 proxmox rsyslogd[1006]: action 'action-2-builtin:omfile' (module 'builtin:omfile') message lost, could not be processed. Check for additional error messages before this one. [v8.2102.0 try https://www.rsyslog.com/e/2027 ]
May 21 00:15:15 proxmox systemd[1]: lvm2-pvscan@230:3.service: Succeeded.
May 21 00:15:15 proxmox rsyslogd[1006]: file '/var/log/daemon.log'[9] write error - see https://www.rsyslog.com/solving-rsyslog-write-errors/ for help OS error: No space left on device [v8.2102.0 try https://www.rsyslog.com/e/2027 ]
May 21 00:15:15 proxmox systemd[1]: Stopped LVM event activation on device 230:3.
May 21 00:15:15 proxmox rsyslogd[1006]: action 'action-2-builtin:omfile' (module 'builtin:omfile') message lost, could not be processed. Check for additional error messages before this one. [v8.2102.0 try https://www.rsyslog.com/e/2027 ]
May 21 00:15:16 proxmox systemd[1]: 100.scope: Succeeded.

Upon investigation I see a 59GB backup image.
Is this image a full snapshot byte for byte, NOT a ZFS style snapshot (which would be much smaller and only store differences?)

I'm also a little concerned about the nvme lines (2-5) is that a physical fault?

 

[spirit]

If you don't use the proxmox backup server, each backup is always a full backup. (byte for bytes, excluding zero + compression).

with the proxmox backup server, you'll have only 1 full + always incremental backups.



(not sure about your nvme physical error, I think you should look at your logs if it's recurrent or not)

 

[jaxjexjox]

If you don't use the proxmox backup server, each backup is always a full backup. (byte for bytes, excluding zero + compression).

with the proxmox backup server, you'll have only 1 full + always incremental backups.



(not sure about your nvme physical error, I think you should look at your logs if it's recurrent or not)

Apologies, I'm baffled.
I use Proxmox server itself, menu on the left:
(Datacenter - then down to backup, just understorage)
Is there another product called "Proxmox backup server" which I install on another machine?


I'm used to using TrueNAS where I can run a ZFS compressed snapshot and it takes very little space.

 

[Dunuin]

Apologies, I'm baffled.
I use Proxmox server itself, menu on the left:
(Datacenter - then down to backup, just understorage)
Is there another product called "Proxmox backup server" which I install on another machine?


I'm used to using TrueNAS where I can run a ZFS compressed snapshot and it takes very little space.

You can use snapshots with Proxmox VE (PVE) too. But snapshots never replace a real backup as you will loose them too in case your pool fails. So in addition to snapshots you should always also do backups. And for backups you can use Vzdump (integrated into PVE) which will waste alot of space or the Proxmox Backup Server (PBS) which is another product that is best installed on an dedicated second server (but you could run it in a VM/LXC or baremetal beside PVE too) which allows for very small backups: https://www.proxmox.com/en/proxmox-backup-server

 

[jaxjexjox]

You can use snapshots with Proxmox VE (PVE) too. But snapshots never replace a real backup as you will loose them too in case your pool fails. So in addition to snapshots you should always also do backups. And for backups you can use Vzdump (integrated into PVE) which will waste alot of space or the Proxmox Backup Server (PBS) which is another product that is best installed on an dedicated second server (but you could run it in a VM/LXC or baremetal beside PVE too) which allows for very small backups: https://www.proxmox.com/en/proxmox-backup-server

I'm embarassed to admit, you're totally correct and this slipped my mind.
I'm so accustomed to my TrueNAS machine behaving well I forget that I also do run other backups off my main array just in case.

Question - are 'normal' zfs snapshots supported, within the UI of Proxmox or do I need to configure these manually from the CLI ?


> "Proxmox Backup Server (PBS) which is another product that is best installed on an dedicated second server (but you could run it in a VM/LXC or baremetal beside PVE too) which allows for very small backups:"


I was thinking about literally just dumping to a second drive in the system - is this viable?
I take it the proper backup solution is the better choice?