timed out for waiting the udev queue being empty


New Member
May 19, 2024
timed out for waiting the udev queue being empty
Gave up waiting for root file system device. Common problems:
- Boot args (cat /proc/cmdline)
- Check rootdelay= (did the system wait long enough?)
- Missing modules (cat /proc/modules; ls /dev)
ALERT! /dev/mapper/pve-root does not exist. Dropping to a shell!

I have exactly the same problem. I have installed the latest version of pve 8.2.2. The root is on an md0 raid1 array. Everything else is on ZFS.

The operating system boots inconsistently; that is, during one restart, it may hang for 2-4 minutes and then load, while during another, it may hang for 5 minutes and fail to load. This happens completely randomly.

The problem is observed specifically during boot-up. No issues have been observed during operation so far.

Key moments are captured in screenshots:

Grub - 1:16

Immediately after Grub - 1:19
Booting Proxmox VE GNU/Linux
Loading Initial ramdisk...

When the OS is loading, it hangs in this position for 2 minutes and then begins to boot. But as we know, after Grub, the boot should start immediately, or at most within 2 seconds.However, in this case, when the OS did not load, it hung on this screen until 03:30, i.e., it hung for 2 minutes and 20 seconds.

Here it writes: Timed out waiting for the udev queue to be empty.
And it hangs like this for almost 2 more minutes, until 05:14.

at 05:14: Timed out waiting for the udev queue to be empty. mdadm: error opening /dev/md?*: No such file or directory.
The root is specifically on this raid.

After another 3 seconds

At this window, it does not respond to the keyboard, nor to ctrl alt del.
After one or two restarts, the system will boot up with a long hang lasting 2-4 minutes.
All hardware components were sequentially replaced from a ZIP kit for testing (motherboard, RAM, power supply, NVMe disks, SAS controllers). Only the processor was not replaced. Therefore, hardware issues can almost certainly be ruled out.

An important observation is that if all HDD and SSD drives are disconnected, leaving only the NVMe drives where the root is located, the system boots immediately without any delays.
It seems like the bootloader doesn't like that there are so many drives in the server—18 in total.

If you need me to send any additional data or command outputs, I'll send them all.
  • What pve version do you use?
  • Does your system not boot at all, or does it boot intermittently like mine?
  • How many disks in you system?
What i didn't realise, you can advance boot grub and select a previous version of pve / pbs
This enabled me to boot correctly
The problem is probably massive, I hope it will be fixed soon.

Do you have this problem after the update too?

Try to boot your pve using the installation iso: advanced mode - Rescue boot.

As I understand it, the problem is in the bootloader, in Rescue boot mode, the download bypasses the regular bootloader.
Probably it helps you.




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