6 minutes ago, rymalco said:

not running dockers

You have a docker image mounted as shown in the next-to-last line of those "cat /proc/mounts" results. Might as well disable docker, delete the image and reclaim its storage.

11 hours ago, trurl said:

You have a docker image mounted as shown in the next-to-last line of those "cat /proc/mounts" results. Might as well disable docker, delete the image and reclaim its storage.

Thanks for tip!

It looks as if VMs might also be enabled since libvirt is being mounted.  If so disabling that might also be a good idea.

On 1/9/2019 at 11:27 PM, limetech said:

If the issue gets reported more often we'll have to dive into kernel source to see what's going on.

Here's another one  (Also added @johnnie.black's solution to the FAQ)

 

Edited January 20, 20197 yr by Squid

On 1/9/2019 at 4:28 PM, johnnie.black said:

 

Try this, it worked for me for an identical error, on the flash drive edit syslinux/syslinux.cfg and add root=sda to the boot option you're using after initrd=/bzroot, e.g.:

 

label Unraid OS
   menu default
   kernel /bzimage
   append initrd=/bzroot root=sda

Johnnie, thank you for posting this! 

 

My situation is a bit different as I'm running Unraid under ESXi, which isn't supported, but has done exactly what I need it to do for years.

 

In my case, everything works perfectly using ESXi 6.0 and ESXi 6.5 but as soon as I tried upgrading to ESXi 6.7 I kept getting the "VFS: cannot open root devise "(null)" or unknown-block(0,0): error -6" message.

 

I tried everything I could think of and had basically decided that ESXi 6.5 was the highest I could use while keeping Unraid.  I added the " root=sda" on each of the append initrd lines, rebooted the VM, and it booted up perfectly.

 

Honestly, I have no idea what this does or why it would make any difference at all, but it fixed booting an Unraid 6.6.6 VM in ESXi 6.7

 

Thanks!

I just ran into this issue as well.

 

I have a very old system built for a customer from nearly 10 years ago now.  It is only ever used as a file server so there was no real reason to touch it.  Well, parts finally started to fail (not the motherboard or processor but the drive cages).  The customer was not interested in upgrading anything except for the unRAID OS version.  I went to update it and of course nothing booted after 6.2.4.  As soon as I put 6.3.5 on the USB drive and attempt to boot I would get the above mentioned error.  I updated the BIOS on the board but that solved nothing.  So some google-fu later I find this thread and the suggestion to add "root=sda" to the syslinux.cfg.  That seems to have worked on the OLD Biostar A760G M2+ board with a Phenom II X4 in it.

 

Not sure what in the kernel between 6.2.4 and 6.3.5 made it stop booting but the "root=sda" trick works fine on this old build.

I'm also getting this error on every upgrade and sometimes just on reboots after 6.6  I'm going to try this and hoping it will do the trick. Original post requesting help.

 

This just happened to me after a reboot on 6.10.0-rc1. Easy to add root=sda in the syslinux.cfg, but saw there was a post on it so just wanted to bring it up as something that's still occurring (though it seems rare).

6 hours ago, timstephens24 said:

This just happened to me after a reboot on 6.10.0-rc1.

Why post about it in this old thread for a very old version?

Because it’s related? 

On 8/22/2021 at 9:59 AM, timstephens24 said:

This just happened to me after a reboot on 6.10.0-rc1. Easy to add root=sda in the syslinux.cfg, but saw there was a post on it so just wanted to bring it up as something that's still occurring (though it seems rare).

 

This also happened to me updating to 6.10.2 (I reset back to 6.9) and then again when coming to 6.10.3.

On 8/22/2021 at 5:02 PM, trurl said:

Why post about it in this old thread for a very old version?

 

I'm having the same "kernel panic" issue when trying to move the USB from a Mac mini 2018 to a Mac mini 2012 hardware. It used to work before, but with the latest UNRAID 7 release, it no longer boots. I've tried to modify /syslinux/syslinux.cfg as

append initrd=/bzroot root=UUID=5befa670-01
append initrd=/bzroot root=/dev/sda1
append initrd=/bzroot LABEL=UNRAID

Nothing works! Any idea why the USB device won't boot to the hardware that used to work?

3 hours ago, SergeV said:

I'm having the same "kernel panic" issue when trying to move the USB from a Mac mini 2018 to a Mac mini 2012 hardware.

See here:

https://forums.unraid.net/topic/194648-vfs-unable-to-mount-root-fs-since-upgrading-from-714-to-72/#findComment-1611793

9 hours ago, JorgeB said:

See here:

https://forums.unraid.net/topic/194648-vfs-unable-to-mount-root-fs-since-upgrading-from-714-to-72/#findComment-1611793

Thank you! I was able to migrate my USB device to the Mac Mini 2012 (legacy EFI boot) using limine binary BOOTX64.EFI and custom limine.conf
I had an additional inconsistent issue during the boot, where sometimes I would get an error:

Isdal Attached SCSI disk umount: /deu: target is busy.
umount: /: not mounted. not found - press ENTER key to reboot...

I had to plug my USB device into another USB port. Maybe it got dusty. The UNRAID USB boot key never appears in the log. UNRAID's init script scans for a partition labeled UNRAID and times out because that device simply never enumerates in time — or at all.