Re: Debian AMD64 boots only at random: how to use labels/fstab/grub

[Bob McGowan <bob_mcgowan@symantec.com>]

I'm only familiar with the ext[23]/xfs filesystem commands which is what 
you appear to be using.  Other FS's have similar tools, I expect.

First, you need to be sure your disks are labeled.  For ext[23], the 
command is 'e2label -L /dev/...' where ... would be sda4 or hdb2, or 
whatever else you have.  For xfs, the command is 'xfs_admin -l /dev/...'

If you have a disk with no label, you would need to add one.  The disks 
must be unmounted before you can make changes, so you'd need to boot 
from a CD as the quickest, easiest way to work with them.  For ext[23], 
the command is 'e2label -L label', for xfs it's 'xfs_admin -L label', 
where 'label' is any name you choose, within the size limits specified 
in the man page for the commands.  Note the lower/upper case option with 
the xfs command.

All recent Debian installs that I've done have created labels for the 
devices created during the install.  These are the name of the mount 
point.  So, if you have a disk that is mounted on '/var' (as you do), 
the default label will be '/var'.

The only issue I have with this is the label chosen for the 'root' 
device.  This is '/', which is not a legal name in the file system, so 
no link is made for the root device, to use with the mount command.  I 
changed the root label on my system from '/' to '/root', so a valid link 
is created.

Now that you have labels on all your disk drives, change the two files 
like this:

  menu.lst:
  from
    kernel          /boot/vmlinuz-2.6.17-2-amd64 root=/dev/sda1 ro
  to
    kernel          /boot/vmlinuz-2.6.17-2-amd64 root=LABEL=/root ro

  fstab (just one example, the rest are similar):
  from
    /dev/sdb1      /var          ext3   defaults      0     2
  to
    LABEL=/var     /var          ext3   defaults      0     2

Reboot.

Bob

Joost Kraaijeveld wrote:
> Hi,
>
> After an update of my kernel to 2.6.17 my machine only boots at random.
> I have googled for a solution and it appears that it happens because of
> the way the harddisks are found during startup . The solution described
> involves using lables in fstab and grub (menu.lst).
>
> But whatever I do, I cannot find a way to add labels in my fstab an grub
> that actually work. Can anyone tell me what I have to do to make my
> machine boot reliable using labels with fstab/grub? I have tried to add
> labels to both fstab and menu.lst but a reboot failed miserably....
>
> Excerpt from my menu.lst
>
> title           Debian GNU/Linux, kernel 2.6.17-2-amd64
> root            (hd0,0)
> kernel          /boot/vmlinuz-2.6.17-2-amd64 root=/dev/sda1 ro
> initrd          /boot/initrd.img-2.6.17-2-amd64
> savedefault
>
>
> My fstab:
>
> # /etc/fstab: static file system information. 
> # 
> # <file system> <mount point>   <type>  <options>       <dump>  <pass> 
> proc            /proc           proc    defaults        0       0 
> /dev/sda1       /               ext3    defaults,errors=remount-ro 0 1 
> /dev/sdb1       /var            ext3    defaults        0       2 
> /dev/sdc1       /home           xfs     defaults        0       2 
> /dev/sdc2       /pgdata         xfs     defaults        0       2 
> /dev/sda5       none            swap    sw              0       0 
> /dev/hdc        /media/cdrom0   udf,iso9660 user,noauto     0       0 
> /dev/fd0        /media/floppy0  auto    rw,user,noauto  0       0 
>
>
> TIA

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature