Boot problem on USB HDD: can't find /mnt in /etc/fstab error

xiongnu · 06-07-2019, 10:13 AM

hi, i have Slackware 14.1 installed on an external usb harddrive. and intend to use SL on different machines that i can get hold of whenever i travel.

I created the boot 'initrd' with the following:

Code:

cd /boot
mkinitrd -c -k 3.10.17-smp -m usb-storage:ehci-pci:ehci-platform -u -w 5 -f ext4 -r '_HDD_UUID'

However, some the machines I can boot SL, others i can't. receiving an error during boot.

Code:

mount: can't find /mnt in /etc/fstab
ERROR: no /sbin/init found on rootdev (or not mounted)

I should also mention that I've Openindiana as well as winXP installed on the same harddrive, partition and fstab are as follows:

Code:

Disk /dev/sdb: 80.0GB
...

Disk identifier: 0x3a393a38

Device    boot   start     end        blocks    id  systems
/dev/sdb1       63        41942879    20971408   7    hpfs/ntfs/exfat
/dev/sdb2   *   49945715   83875364    20964825  bf  solaris
/dev/sdb3       83875365   85867424    996030    82   linux swap
/dev/sdb4   *   85867425   125805014   19968795   83   linux


root@ :#  cat /etc/fstab
'swap partition UUID'    swap   swap  defaults  0 0
'install partition UUID'    /      ext4  defaults  1 1
/dev/sda1    /mnt/win   ntfs-3g  fmask=133, dmask=022  1 0
devpts       /dev/pts   devpts   gid=5, mode=620     0 0 
proc         /proc       proc     defaults           0  0 
tmpfs        /dev/shm    tmpfs    defaults            0  0

If it matters:
Of the machines that i can boot:
My two home PCs (one is HP, the other is homebuilt AMD machine with K8N Neo motherboard), and a Sony Vaio netbook.

Of the machines that i can't boot:
A nobrand microtower with Biostar P4M900-M4 MB
Dell OptiPlex 5060

Any suggestion how to fix this?

Chuck56 · 06-07-2019, 10:25 AM

Try using UUIDs instead of /dev/sd* in the /etc/fstab file. Run the "blkid" command as root to get the UUIDs on a machine that works.

bassmadrigal · 06-07-2019, 10:36 AM

Are you actually using the UUID of your harddrive in the mkinitrd command? I'm not sure if yours is edited to not show the UUID (which it doesn't really matter if those are made public or not) or if that is the actual command you ran.

And you'll definitely want to switch your /etc/fstab to UUIDs as if there is another harddrive or USB drive (or sometimes even cardreaders), it can affect your device names (/dev/sda, /dev/sdb, etc). Using UUIDs in your fstab will make sure that you don't run into issues with those changing. My guess is your problem is caused by the lack of UUIDs in your fstab and once you fix that, it will likely fix your problem.

ehartman · 06-07-2019, 10:51 AM

Quote:

Originally Posted by xiongnu

Of the machines that i can't boot:
A nobrand microtower with Biostar P4M900-M4 MB
Dell OptiPlex 5060

Any suggestion how to fix this?

Could it be that the machines you cannot boot have UEFI enabled, which means they will need a FAT formatted UEFI partition with kernel and initrd ON your external hard disk?

xiongnu · 06-07-2019, 11:36 AM

Quote:

Originally Posted by bassmadrigal

Are you actually using the UUID of your harddrive in the mkinitrd command? I'm not sure if yours is edited to not show the UUID (which it doesn't really matter if those are made public or not) or if that is the actual command you ran.

And you'll definitely want to switch your /etc/fstab to UUIDs as if there is another harddrive or USB drive (or sometimes even cardreaders), it can affect your device names (/dev/sda, /dev/sdb, etc). Using UUIDs in your fstab will make sure that you don't run into issues with those changing. My guess is your problem is caused by the lack of UUIDs in your fstab and once you fix that, it will likely fix your problem.

these are the actual mkintrd and fstab:

Code:

mkinitrd -c -k 3.10.17-smp -m usb-storage:ehci-pci:ehci-platform -u -w 5 -f ext4 -r UUID=f487c8e1-a959-4cfa-8a2e-c8718660dcaf

UUID=6faddc5e-8660-406d-a8b1-da1124368b0e        swap             swap        defaults         0   0
UUID=f487c8e1-a959-4cfa-8a2e-c8718660dcaf        /                ext4        defaults         1   1
UUID=8AA0E4F5A0E4E8A1        /mnt/win         ntfs-3g     fmask=133,dmask=022 1   0
#/dev/cdrom      /mnt/cdrom       auto        noauto,owner,ro,comment=x-gvfs-show 0   0
/dev/fd0         /mnt/floppy      auto        noauto,owner     0   0
devpts           /dev/pts         devpts      gid=5,mode=620   0   0
proc             /proc            proc        defaults         0   0
tmpfs            /dev/shm         tmpfs       defaults         0   0

I've modified 'fstab' to use UUIDs only, tried on the Dell Optiplex 5060 machine again, still got the same boot error.

Screenshot of error

colorpurple21859 · 06-07-2019, 12:17 PM

Try adding mbcache to mkinitrd

xiongnu · 06-07-2019, 12:46 PM

Quote:

Originally Posted by ehartman

Could it be that the machines you cannot boot have UEFI enabled, which means they will need a FAT formatted UEFI partition with kernel and initrd ON your external hard disk?

UEFI boot is disabled on this Dell machine I had issue with, it uses Legacy boot.

Chuck56 · 06-07-2019, 01:56 PM

Based on the error screen the issue is most likely a missing module in the initrd. I wonder if an initrd similar to the one offered with a Slackware installation USB is the way to go for your use case. Maybe the "usbboot.img" found in the usb-and-pxe-installers directory of a 14.1 mirror can point the way to creating a universally bootable USB HDD for your mix of PCs?

bassmadrigal · 06-07-2019, 02:22 PM

You could try running /usr/share/mkinitrd/mkinitrd_command_generator.sh on the problematic machine and add any missing modules it suggests to your initrd.

bormant · 06-09-2019, 03:19 AM

Try to increase delay to -w 10, does it help?

Skaendo · 06-09-2019, 05:05 AM

Are you using a USB3 or USB2 port?

If you are trying to boot legacy, you probably need to be using a USB2 port.