#3513 Issue open: ReaR - rsync recover very slow

cristiansimioni opened issue at 2025-08-21 09:17:

Requesting support or just a question

Why is the rsync on rear recover so slow?

Platform

Linux x64

Output

Rsync poor performance (3KiB/s). Please check additional information.

Additional information

Scenario: trying to recover multiple Red Hat 8.10 virtual machines using rsync. Here is the /etc/rear/local.conf:

AUTOEXCLUDE_PATH=( /media /net /vhe )
OUTPUT=ISO
BACKUP=RSYNC
BACKUP_URL=rsync://xxx.xxx.xxx.xxx/backup/images

EXCLUDE_MOUNTPOINTS=( "/backup" )
AUTOEXCLUDE_MULTIPATH=y

USE_RESOLV_CONF=( "no" )
FIRMWARE_FILE="no"
MODULES=()

EFI_BOOTLOADER="1"
GRUB2_UEFI="1"
CREATE_SHIM="yes"
SECURE_BOOT_BOOTLOADER="/boot/efi/EFI/redhat/shimx64.efi"

Using ReaR 2.6:

rear --version
Relax-and-Recover 2.6 / 2020-06-17

This creates the rear.iso and the backup folder, with the OS data, on my backup server (bkpsrv) at /backup/images/. My virtual machines are running on a different physical host than the bkpsrv. In the case I need to restore a specific virtual machine, I move the iso image from bkpsrv to the desired physical host, recreate the VM, attach the iso and boot.

However, when starting the rsync to the /mnt/local, the speed is limited to 3KiB/s. I can see that ReaR is using the following command from the rear log:

rsync --sparse --archive --hard-links --numeric-ids --stats root@xxx.xxx.xxx.xxx:/backup/images/<hostname>/backup/ /mnt/local/

Image

I have tested the network on both directions and I can transfer files using rsync quite fast (100MB/s).

On the rear rescue console, if I run the very same command, it goes really fast:

Image

What am I missing?

[Export of Github issue for rear/rear.]