Created attachment 1842343 [details]
Screenshot showing the crash

Description of problem:

Trying to automatically install a QEMU/KVM over the network (PXE+HTTP) with RHEL8.5, I see that 60% of the time the switchroot to stage2 fails due to not having the /dev/root device.

In the rd.debug log (see attached), I can see that /dev/loop2 which is the "dmsetup overlay" has EXT4 errors:

[   28.178773] loop: Write error at byte offset 29511680, length 4096.
[   28.179856] loop: Write error at byte offset 29515776, length 4096.
[   28.181013] loop: Write error at byte offset 29519872, length 4096.
[   28.182207] loop: Write error at byte offset 29523968, length 4096.
[   28.184361] blk_update_request: I/O error, dev loop2, sector 57640 op 0x1:(WRITE) flags 0x800 phys_seg 1 prio class 0
[   28.185819] blk_update_request: I/O error, dev loop2, sector 57648 op 0x1:(WRITE) flags 0x800 phys_seg 1 prio class 0
[   28.187940] blk_update_request: I/O error, dev loop2, sector 57656 op 0x1:(WRITE) flags 0x800 phys_seg 1 prio class 0
[   28.189591] blk_update_request: I/O error, dev loop2, sector 57664 op 0x1:(WRITE) flags 0x800 phys_seg 1 prio class 0
...


Switchroot to /dev/loop2 then fails and we get the emergency prompt:

Warning: /dev/root does not exist
Entering emergency mode. Exit the shell to continue.
...


This is new with RHEL8.5.
I started 20 times the installation of the same system with RHEL8.4 and this was always a success.
With RHEL8.5, the failure happened ~60% of the time (runs 1, 2, 3, 4 and 7 were a success, all other failed similarly).


Version-Release number of selected component (if applicable):

RHEL8.5 DVD


How reproducible:

Very easily on my QEMU/KVM (BIOS mode)

Steps to Reproduce:

1. Boot over PXE

Actual results:

Crash as Switch Root to stage2


Expected results:

No crash