SCSI Drive Labels and Lilo (w/ wailing and gnashing of teeth)

enorbet · 01-16-2014, 11:47 AM

Hello
OK I've googled around and found an LQ thread which linked Volume Labels and I commonly label all the important partitions (but haven't used devlabel) and I agree that

Quote:

Originally Posted by tldp-Partition How To

2.1.2. Name Assignment

Under (Sun) Solaris and (SGI) IRIX, the device name given to a SCSI drive has some relationship to where you plug it in. Under linux, there is only wailing and gnashing of teeth.

with the caveat that now that there are mobos with different versions of SATA on the same board, this is even worse.

Since I have been engaging in some of said gnashing due to the facts that

1) I do NOT want to use UUID
2) I do NOT want to use an initrd
3) I prefer to NOT use Grub, but rather continue with Lilo
and,
4)The LQ thread said initrd was needed even when using Drive Labels.

So before I grind them to nubs, does anyone know if initrd is indeed required for Drive Labels (I can't find a definitive answer) or if there is some way to insure that udev's silliness is overcome and drives/partitions always get the same label, especially SATA drives no matter which port I plug into? (and still meet my above preferences?)

Thank you in advance for any help offered.

Didier Spaier · 01-16-2014, 11:53 AM

There is absolutely no need to use an initrd to designate your partitions by LABEL in /etc/fstab and /etc/lilo.conf.

PS Here is what says "man lilo.conf:"

Code:

root=<root-device>
This specifies the device that should be mounted as root. It may be specified as a global option. If
the special name current is used, the root device is set to the device on which the root file system is
currently mounted. If the root has been changed with -r , the respective device is used. If the vari‐
able `root' is omitted, the root device setting contained in the running kernel image is used. Warn‐
ing: This can induce to an unbootable system!

The root filesystem may also be specified by a LABEL= or UUID= directive, as in '/etc/fstab'. In this
case, the argument to root= must be enclosed in quotation marks, to avoid a syntax error on the second
equal sign, e.g.:

root="LABEL=MyDisk"
root="UUID=5472fd8e-9089-4256-bcaa-ceab4f01a439"

Note: The command line root= parameter passed to the kernel will be: 'root=LABEL=MyDisk'; i.e., with‐
out the quotation marks. If the root= parameter is passed from the boot time boot: prompt, no quotes
are used. The quotes are only there to satisfy the requirements of the boot-installer parser, which
treats an equal sign as an operator. The kernel command line parser is very much simpler, and must not
see any quotation marks. Simply stated, only use the quotation marks within /etc/lilo.conf.

Now man fstab:

Code:

              Instead  of  giving  the  device explicitly, one may indicate the (ext2 or xfs) filesystem that is to be
              mounted by its UUID or  volume  label  (cf.   e2label(8)  or  xfs_admin(8)),  writing  LABEL=<label>  or
              UUID=<uuid>, e.g., `LABEL=Boot' or `UUID=3e6be9de-8139-11d1-9106-a43f08d823a6'.  This will make the sys‐
              tem more robust: adding or removing a SCSI disk changes the disk device name but not the filesystem vol‐
              ume label

PPS Use 'e2label' or 'tune2fs' to label existing (already formatted) ext2/ext3/ext4 partitions. Use 'xfs_admin' for XFS partitions.

enorbet · 01-16-2014, 12:53 PM

Thank you Didier. I was up all night and got exhausted by the time I got to trying to comprehend how partition label would overcome udev's disk assignment, other than with an initrd, and I really don't want to head down that road.

Note: I used Clonezilla to clone an SATA-2 drive to a much larger SATA-3 and the port change would not be overcome in UEFI/BIOS by setting it as first boot device. So I am very grateful and still tired LOL but I will do this today.

Didier Spaier · 01-16-2014, 01:20 PM

LABEL (as well as UUID) does not overcome the device name (allocated by udev if we use it) but are other metadata linked to the disk partition.

Device name can change. UUID will never change. LABEL will change only if a command is run to change it.

PS I can't see any inconvenience in using the UUID (I do), but use what you're comfortable with.

EDIT. I was wrong, UUID can change, see next post from lecho.

lecho · 01-17-2014, 03:47 PM

Just a short comment to

Quote:

Originally Posted by Didier Spaier

...
Device name can change. UUID will never change. LABEL will change only if a command is run to change it.
...

UUID can be changed using e.g. tune2fs (option -U), gparted. Resizing/reformatting of a partition also changes its UUID.

Didier Spaier · 01-17-2014, 03:56 PM

Quote:

Originally Posted by lecho

Just a short comment to
UUID can be changed using e.g. tune2fs (option -U), gparted. Resizing/reformatting of a partition also changes its UUID.

I stand corrected. I learned something today, thanks lecho

PS I see that you live in Warsaw. Maybe you'd like to join the Polish translation team for slint? (see links in my sig :-)

lecho · 01-17-2014, 04:12 PM

You're welcome,