[SOLVED] Incremental backup takes many hours

abranca

Active Member
Mar 6, 2017
45
5
28
36
hi guys,
I am posing a problem that is bothering me a bit.

I have a container running iredmail as mailserver
The disk of this container is 1tb and the total space occupied is about 195gb.

The first backup, with compression, is about 90gb and so far so good.
The incremental backups, the last one of last night copied only 2.4gb of files (compressed 1.2gb), take about 5 hours. is this normal according to you?
All other machines take a few minutes.
The speed appears very low (146Kb/s) while for other CTs and VMs it is much higher.
Could it be that, by copying only single files of the emails, the time for checking and backup is so much and the speed so low?

PBS is on a Proxmox VM with 4 cores and 4 gigs of ram and destination is NFS share.

I attach here the log of the backup of yesterday.

Thank you all for your advice!

last backup log:
Code:
Proxmox
Virtual Environment 6.3-6
Search
Container 105 (email) on node 'kve'
User name:
Only Errors:
Server View
Logs
()
INFO: starting new backup job: vzdump 105 --quiet 1 --mailto alessandro.branca@xxxxx.com --compress zstd --mailnotification failure --mode snapshot --storage pbs-posta
INFO: Starting Backup of VM 105 (lxc)
INFO: Backup started at 2021-04-09 20:30:03
INFO: status = running
INFO: CT Name: email
INFO: including mount point rootfs ('/') in backup
INFO: backup mode: snapshot
INFO: ionice priority: 7
INFO: create storage snapshot 'vzdump'
INFO: creating Proxmox Backup Server archive 'ct/105/2021-04-09T18:30:03Z'
INFO: run: lxc-usernsexec -m u:0:100000:65536 -m g:0:100000:65536 -- /usr/bin/proxmox-backup-client backup --crypt-mode=none pct.conf:/var/tmp/vzdumptmp10156_105/etc/vzdump/pct.conf root.pxar:/mnt/vzsnap0 --include-dev /mnt/vzsnap0/./ --skip-lost-and-found --exclude=/tmp/?* --exclude=/var/tmp/?* --exclude=/var/run/?*.pid --backup-type ct --backup-id 105 --backup-time 1617993003 --repository xxxxx@pam@192.168.1.7:pbs-posta
INFO: Starting backup: ct/105/2021-04-09T18:30:03Z
INFO: Client name: kve
INFO: Starting backup protocol: Fri Apr  9 20:30:03 2021
INFO: Upload config file '/var/tmp/vzdumptmp10156_105/etc/vzdump/pct.conf' to 'xxxxxxx@pam@192.168.1.7:8007:pbs-posta' as pct.conf.blob
INFO: Upload directory '/mnt/vzsnap0' to 'xxxxx@pam@192.168.1.7:8007:pbs-posta' as root.pxar.didx
INFO: root.pxar: had to backup 2.48 GiB of 199.24 GiB (compressed 1.12 GiB) in 17771.57s
INFO: root.pxar: average backup speed: 146.28 KiB/s
INFO: root.pxar: backup was done incrementally, reused 196.77 GiB (98.8%)
INFO: Uploaded backup catalog (41.77 MiB)
INFO: Duration: 17772.02s
INFO: End Time: Sat Apr 10 01:26:15 2021
INFO: cleanup temporary 'vzdump' snapshot
INFO: Finished Backup of VM 105 (04:56:14)
INFO: Backup finished at 2021-04-10 01:26:17
INFO: Backup job finished successfully
TASK OK
 
Last edited:

spirit

Famous Member
Apr 2, 2010
5,782
678
133
www.odiso.com
lxc incremental backup need to reread the full disk, to do the diff vs what is stored in pbs, so yes,it can take time.

use qemu vm if you want to have it faster. (qemu is tracking block changes, so no need to reread the full disk)
 

abranca

Active Member
Mar 6, 2017
45
5
28
36
lxc incremental backup need to reread the full disk, to do the diff vs what is stored in pbs, so yes,it can take time.

use qemu vm if you want to have it faster. (qemu is tracking block changes, so no need to reread the full disk)
thank you for your clarification.
you have been very kind.

obviously there is no way to convert a lxc to qemu vm, right?
i have to make the vm and import the data, correct?
 

abranca

Active Member
Mar 6, 2017
45
5
28
36
Yes and yes. :)
thanks for your reply!

i've opted to create a new vm and transfer the data. definitely faster and more within my reach. i've read a few posts on how to turn a ct into a vm but it's definitely out of my skill set for now.
 

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get your own in 60 seconds.

Buy now!