Clonezilla, how to improve the backup speed

[Srinivasa]

Hello,
I am using the latest Clonezilla to create a backup image (using partclone option), I tried all possible options of clonezilla, but I am getting only 26GB/min max speed. Is there any way to improve the speed?I even tried to increase buffer size input to parclone, but it did not help.partclone command sample from clonezilla.log
Running: partclone.ext4 -z 671088640 -N -L /var/log/clonezilla//partclone.log -c -s /dev/nvme4n1p2 --output - | zstd -c -T0 -3 > "/home/partimag/e8ea6aa21eae-2026-0305-0506-img/nvme4n1p2.ext4-ptcl-img.zst" 2> /tmp/img_out_err.RlihxhI have s machine with following configuration:
Disk Type : NVME: WD_BLACK SN8100
Source Disk: 1.2TB used out of 4TB
Destination Disk: 1.8TB
PCI5 langes.
RAM : 384GiB
AMD EPYC 9255 24-Core Processor, threads=48Any suggestions are highly welcome.Thanks,Srinivasa

[Steven Shiau]

Hi,
Which version of Clonezilla live did you use?
Have you tried Clonezilla live 3.3.1-35 or 20260220-questing?
https://clonezilla.org/downloads.php
You can try to enter expert mode and check the option "-edio" of Clonezilla.
If you run partclone directly, try to add the option "--read-direct-io".

[Srinivasa]

I used clonezilla-live-20260220-questing-amd64.iso and clonezilla-live-3.3.1-35-amd64.iso
if I use -q1 i.e dd , I am getting 168GB/s, but -q2 i.e partclone, I am getting 26GB/s. I am using Clonezilla batch mode.

I tried --read-direct-io with partclone.ext4, I see no difference

**Results of partclone.ext4:
**
sudo partclone.ext4 --read-direct-io -L /media/DND/test_partclone.log -c -s /dev/nvme3n1p1 --output "/media/DND/test.uncomp"
Partclone v0.3.27 http://partclone.org
Starting to clone device (/dev/nvme3n1p1) to image (/media/DND/test.uncomp)
Reading Super Block
Calculating bitmap... Please wait...
Elapsed: 00:00:03, Remaining: 00:00:00, Completed: 100.00%
Total Time: 00:00:03, 100.00% completed!
done!
File system: EXTFS
Device size: 2.0 TB = 488376576 Blocks
Space in use: 1.8 TB = 448398522 Blocks
Free Space: 163.8 GB = 39978054 Blocks
Block size: 4096 Byte
Elapsed: 00:00:44, Remaining: 01:08:21, Completed: 1.06%, 26.58GB/min,

**Results of partclone.dd:
**
sudo partclone.dd --read-direct-io -L /media/DND/test_partclone.log -s /dev/nvme3n1p1 --output "/media/DND/test.uncomp"
Partclone v0.3.27 http://partclone.org
Starting to clone/restore (/dev/nvme3n1p1) to (/media/DND/test.uncomp) with dd mode
Calculating bitmap... Please wait... done!
File system: raw
Device size: 2.0 TB = 3907012608 Blocks
Space in use: 2.0 TB = 3907012608 Blocks
Free Space: 0 Byte = 0 Blocks
Block size: 512 Byte
Elapsed: 00:00:42, Remaining: 00:15:33, Completed: 4.31%, 123.08GB/min,
Current block: 168275968, Total block: 3907012608, Complete: 4.31%