Backup to NFS share is too fast


Renowned Member
Mar 7, 2014
Hello all,

I have configured Proxmox to backup containers and VM's to a NFS share on my NAS. The containers and VM's are on a M.2 SSD disk.
When the backup start it will try to push the backup with high speed to my NAS, but it is too fast so some mechanism will trottle it back so the NAS can write it to the NFS share.

Is there someway a configuration parameter that sents the backup image with lower speed so that the NAS can process it without having to trottle back?

On an older server (with older hardware) this backup was made in less then 1 minute. Also the VM's that are being backuped via "snapshot" mode becomes unresponsive.

INFO: starting new backup job: vzdump 200 --storage synnas --node proxmox --quiet 1 --compress lzo --mailto --mailnotification failure --mode snapshot
INFO: Starting Backup of VM 200 (qemu)
INFO: Backup started at 2019-11-15 00:30:02
INFO: status = running
INFO: update VM 200: -lock backup
INFO: VM Name: Mail
INFO: include disk 'sata0' 'local:200/vm-200-disk-0.raw' 50M
INFO: include disk 'sata1' 'local:200/vm-200-disk-1.qcow2' 8G
INFO: backup mode: snapshot
INFO: ionice priority: 7
INFO: creating archive '/mnt/pve/synnas/dump/vzdump-qemu-200-2019_11_15-00_30_02.vma.lzo'
INFO: started backup task 'fd06f200-8cde-4cc7-8480-d0e2f1be8352'
INFO: status: 12% (1052901376/8642363392), sparse 0% (51392512), duration 3, read/write 350/333 MB/s
INFO: status: 24% (2124808192/8642363392), sparse 1% (142565376), duration 6, read/write 357/326 MB/s
INFO: status: 35% (3029467136/8642363392), sparse 1% (150032384), duration 9, read/write 301/299 MB/s
INFO: status: 38% (3360161792/8642363392), sparse 1% (150208512), duration 130, read/write 2/2 MB/s
INFO: status: 39% (3454337024/8642363392), sparse 1% (150274048), duration 147, read/write 5/5 MB/s
INFO: status: 50% (4349755392/8642363392), sparse 1% (150667264), duration 150, read/write 298/298 MB/s
INFO: status: 54% (4717150208/8642363392), sparse 1% (150720512), duration 153, read/write 122/122 MB/s
INFO: status: 57% (4987027456/8642363392), sparse 3% (306872320), duration 211, read/write 4/1 MB/s
INFO: status: 64% (5541986304/8642363392), sparse 3% (315744256), duration 214, read/write 184/182 MB/s
INFO: status: 65% (5665325056/8642363392), sparse 3% (318050304), duration 241, read/write 4/4 MB/s
INFO: status: 75% (6484656128/8642363392), sparse 3% (342933504), duration 244, read/write 273/264 MB/s
INFO: status: 77% (6716522496/8642363392), sparse 3% (343134208), duration 293, read/write 4/4 MB/s
INFO: status: 82% (7168851968/8642363392), sparse 4% (366333952), duration 296, read/write 150/143 MB/s
INFO: status: 85% (7393116160/8642363392), sparse 4% (366673920), duration 329, read/write 6/6 MB/s
INFO: status: 90% (7864451072/8642363392), sparse 4% (371290112), duration 332, read/write 157/155 MB/s
INFO: status: 93% (8054505472/8642363392), sparse 4% (372817920), duration 371, read/write 4/4 MB/s
INFO: status: 96% (8364425216/8642363392), sparse 4% (377544704), duration 384, read/write 23/23 MB/s
INFO: status: 100% (8642363392/8642363392), sparse 4% (392134656), duration 385, read/write 277/263 MB/s
INFO: transferred 8642 MB in 385 seconds (22 MB/s)
INFO: archive file size: 4.29GB
INFO: delete old backup '/mnt/pve/synnas/dump/vzdump-qemu-200-2019_11_12-08_46_40.vma.lzo'
INFO: Finished Backup of VM 200 (00:07:06)
INFO: Backup finished at 2019-11-15 00:37:08
INFO: Backup job finished successfully
Thank you for the redirection.

This command works great. I have set a limit to about 65000kbps to test, but it still goes to 1MB/sec.
I guess I will check my network and NAS configuration.

Found the issue.

My backups had to be routed through opnsense (fw) to another subnet. For somehow the traffic looks like a saw, I have to find out why...
But the workaround is to have a direct connection from Proxmox to the NFS share on the NAS so the backup will be made in the same broadcast domain. This works like a charm.
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