hey there, 

 

 I was hoping to get some direction on what to try next. My server won't boot after I gracefully powered it down last night. 

 

This is the error: 

Kernel Panic - not syncing: VFS: Unable to mount root fs on unknown -block (0,0)

 

what I tried after reading some of the other threads: 

- chkdsk on the flash drive - comes out clean 

- re-formated and re-initiated the USB stick with backed up config folder - still crashes with the same error 

 

I'm currently running Memtest and will leave it on overnight, but I somehow don't think a bad memory will be the culprit here. Is there anything else I can try? What are my options after the Memtest comes out clean?

 

thanks in advance

Edited December 5, 20187 yr by daan_SVK

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

 

3 hours ago, 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

 

thanks for the reply, 

 

I have updated the config file as you suggested, then I just get: 

VFS: Cannot open root device "sda" or unknown-block (0,0): error -6

Please append a correct "root=" boot option: here are the available aprtitions: 

0800     3052392 sda

 driver: sd

  0801   30523375 sda1 c307e18-01

 

memtest ran twice without reporting an error. It fails on the same spot when booting so I'm really not suspecting the RAM to be the culprit here. 

 

thanks again for any feedback 

 

Edited December 3, 20187 yr by daan_SVK

The original post suggested that there is a problem reading the USB stick.    Have you tried seeing if you can boot off a different USB stick?

 

i do not see how the suggested fix of adding /root=sda could EVER have worked even for the person who suggested it.   

14 minutes ago, itimpi said:

i do not see how the suggested fix of adding /root=sda could EVER have worked even for the person who suggested it.   

It worked for me with a similar error, but if it didn't for the OP so it's similar but not the same, I suspect so since his flash drive stopped working without a release or hardware change, unlike the other case, but no harm in trying.

21 minutes ago, johnnie.black said:

It worked for me with a similar error, but if it didn't for the OP so it's similar but not the same, I suspect so since his flash drive stopped working without a release or hardware change, unlike the other case, but no harm in trying.

Fair enough.   The reason I thought it was strange is that /root is never on /dev/sda so it is not clear how this helped.

1 minute ago, itimpi said:

so it is not clear how this helped.

I don't why it worked, but it did, I only tried because that was what appeared in the error, to append a correct root, and sda and sda1 were the listed partitions options, it worked with either, curiously it even worked when I added another flash drive as sda making Unraid sdb, it still worked with root=sda, so likely something just needed to skip that step.

 

Oh, and for the OP, try redoing your flash drive, backup current one, format and create a new install and then restore only the config folder from the backup.

Oh, and for the OP, try redoing your flash drive, backup current one, format and create a new install and then restore only the config folder from the backup.

I will do this next as I have 4 clean passes on memtest this morning.

I didn't have the latest version running, when redoing the sticks, should I just download the newest version of Unraid?

Sent from my ONEPLUS A6003 using Tapatalk

23 minutes ago, daan_SVK said:

should I just download the newest version of Unraid?

Yes, though if you're coming from and older release best to read the update notes.

9 hours ago, itimpi said:

The reason I thought it was strange is that /root is never on /dev/sda so it is not clear how this helped.

It isn't referring to /root (the home directory of the root user) or even to / (the root of the Unraid file system), but to where the initial ramdisk root file system (bzroot) is located, so that it can be decompressed and loaded. I believe

append initrd=/bzroot root=/dev/sda1

is the precise form but, as johnnie.black discovered, it seems to work even with a rather vague specification.

So do you think it is still worth to try to boot with 

 

append initrd=/bzroot root=/dev/sda1

First try without, only if you get that error again.

ok, so I downloaded the latest version and set up the USB key from scratch, only replacing the CONFIG folder. 

 

the server now boots up, but I only get the banner from the GUI, nothing else 

 

 

Edited December 4, 20187 yr by daan_SVK

On the flash drive, delete config/plugins/dynamix.plg, reboot and the GUI will come up.

21 hours ago, johnnie.black said:

On the flash drive, delete config/plugins/dynamix.plg, reboot and the GUI will come up.

all sorted, thank you so much for your help. 

 

I ended up copying the config over to a fresh copy of 5.3, then just upgrading directly to the latest version. I, however don't trust this USB stick, so I'll be migrating the OS to a new one

 

thanks again for all the help, this community truly is awesome!