After you discover how it works under the hood, you will follow the recommended way : Local PBS then WAN PBS Remote Sync from.
Give a try , I bet on no more QEMU guest agent stopped with a local PBS.
Root cause isn't QEMU guest agent itself, others services can fail too.
I'd had same problem with too slow HDD on PBS side.
Too slow PBS impacts source guest activity , timeout up to crash
( see simulated example here )
Fleecing is mandatory for...
I did a quick test to reproduce this backup "hang" issue, and the results are pretty clear. It seems Backup Fleecing is exactly what we need for these kinds of bottlenecks.
My test setup:I tried to simulate a "worst-case scenario" with a...
again, sorry for my english wording...
Do you get the point of "Stop mode" backup ?
"Stop mode" backup is still "live".
Fleecing option is mandatory to mitigate.
https://forum.proxmox.com/threads/backup-sync-performance-over-vpn.164450/post-835072
Update:
after a bit of research I think that the error in the dmesg logs has little if anything to do with the issue I described.
Thats related to a bug (?) of the i40e driver, as I understand it: at first the interface tries to filter the vlan...
if downtime isn't critical, if whole reading source isn't too long, the safest is
schedule shutdown guest, then backup offline, then start guest after Backup done using hook script
Reminder : during backup, I/O writes are sent to PBS before within guest itself, it's a "copy-before-write" méthode.
There is fleecing option to mitigate.
it's known issue when PBS is slower than guest I/O usage.
guest is slowdown up to crash some apps if timeout
because snapshot is done when guest is shutdown state, then guest started directly while backup started concurrently.
For Windows to properly report used memory to PVE you need:
- Virtio Balloon driver and service installed and running (installed and enabled automatically with the VirtIO ISO installer). Don't confuse this with QEMU Agent, which does different...
No. It is read completely, to seek and find modified chunks. Look at "write: 0 B/s" in every line ;-)
In a simplified nutshell: the source is read chunk by chunk. The chunk is hashed. That checksum is sent to the PBS. The PBS notices that a...
why I won't see any snapshot being taken of the VM during the backup
As far as i know, for backups qemu creates it's own "snapshot", there are no snapshots created on the storage / file system itself.
snapshot as volume chain
That's for...
Hi, @pulipulichen
You posted only a screenshot and to make matters worse, it doesn't show all the logs' content (the wrapped parts).
If we could see the log in the CODE blocks (this < / > icon above), maybe we could help more.
Anyway, what I...
Full read of VM's source disk is required when VM is shutdown.
Then Dirty map skip full read only on next backup, because dirty map is managed by qemu process of the VM
The config file is already included in the backup archive.
How I solved it:
You can write a note to each VM. I added the "qm set ..." commands as a note. So after a restore I just copy the commands from the restored note and paste it into the...