USB recovery disk Ubuntu 20.04 doesn't always find correct disk/partition by device name

[Rob Gee]

Hello,

I'm trying to create a USB recovery disk so that I can do a system restore for a few machines running Ubuntu 20.04.

The process works fine but sometimes during a restore it will not find the correct disk (i.e. sda1). I have seen that one solution is to use the UUID of the device, but in my case the device UUID will vary depending on the client that is being restored.

Is there any other solution to this? The target device drive will always be the same size (i.e. 512GB) and the other drives will always be more than this. So is there a way to configure clonezilla to look for a device with a fixed size?

thanks

[Steven Shiau]

This issue is related to Linux kernel. You can refer to this:
https://drbl.org/fine-print.php?path=./faq/2_System/133_random_block_device_name.faq#133_random_block_device_name.faq
Do you have one disk or multiple disks in your case?
For the destination disk, maybe you can refer to this doc:
https://clonezilla.org/advanced/reserved-word-ocs-sr.php

Steven

[Rob Gee]

Hi Steven,

Thank you for the clear response.

Do you have one disk or multiple disks in your case?
My use case has multiple physical disks, usually a M2.SSD boot drive and
then 2 HDD direct attached storage drives.

In your referenced documentation link, it indicates that this problem
occurs because after version 5.3 asynchronous scanning of devices was
introduced as a feature. The documentation also states it's possible to
turn off asynchronous scanning using the following:
scsi_mod.disable_async_probing=<driver>[,<driver>]</driver></driver>

Would it be possible to have clonezilla use this configuration of disabling
asynchronous scanning of devices? I think that would solve my and others'
problems.

Forgive my ignorance, but I'm unclear how clonezilla scans for devices and
if it's possible to modify this configuration setting.

thank you for your help in this wonderful product.

-Rob

[Rob Gee]

Hi Steve,

I realize I can edit the grub.cfg file to include the parameter to disable asynchronous scanning. It seems to work and fixes my problem.

Thanks for your help!
Rob

[Steven Shiau]

Hi Rob,
Thanks for your feedback. It's great to know you have solved this issue.
If you can, please describe more about how you disable asynchronous scanning in your case. It would be great for others to refer to in the future if they encounter similar issue.

Steven

[Rob Gee]

Hi Steven,

Unfortunately after more testing, what I thought fixed my problem actually
didn't.

Maybe you have an additional idea, but this is what I thought worked (it
succeeded for 5 straight tests, and then failed)

1.I created an image backup of my boot disk using clonezilla.
2. Used clonezilla to create an .iso image of that backup.
3. Created a bootable USB from the iso.
4. In the bootable usb there is a boot/grub/grub.cfg file that I edited to
include the option to disable asynchronous scanning:
i.e
$linux_cmd /live/vmlinuz boot=live scsi_mod.disable_async_probing=ahci
union=overlay username=user config components noswap edd=on nomodeset
enforcing=0 locales=en_US.UTF-8 keyboard-layouts=NONE
ocs_live_run="ocs-live-restore" ocs_live_extra_param="-g auto -e1 auto -e2
-c -r -j2 -srel -scr -p choose restoredisk recoveryimage sda"
ocs_live_batch="yes" vga=788 ip= net.ifnames=0 quiet nosplash
i915.blacklist=yes radeonhd.blacklist=yes nouveau.blacklist=yes
vmwgfx.enable_fbdev=1
(to find the driver ahci i used the command lsscsi)
5. I thought this worked, but it didn't.

Maybe my syntax or order is wrong. If you have any idea please let me know.

thanks,
Rob

[Steven Shiau]

@Rob,
Do you have any further progress about this?
You mentioned, it succeeded for 5 straight tests, and then failed...
One thing I'd like to ask is, did you test on the same machine? Same hardware? Or?

Steven

[Steven Shiau]

To be honest, I have no idea actually.
If anyone on this forum has some ideas about this, please share. Thank you very much.

Steven