Re: linux servers that do not boot up on /dev/sda make me grumpy ...

From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Sun, 20 Jan 2013 02:59:17 +0000 (UTC)
Message-ID: <pan.2013.01.20.02.59.38_at_gmail.com>

On Sat, 19 Jan 2013 16:22:29 -0800, John Hurley wrote:

> From my blog ...
> http://grumpyolddba.blogspot.com/2013/01/linux-servers-that-do-not-boot-
up-on.html
> ...
>
> Something very strange perhaps about changes in linux 6.2 or how it
> starts up?
>
> Not sure where it started or why ... took me a long time and oracle
> support a long time to get us a fix!
>
> Some weird esoteric stuff here ... dracut ... remove lpfc module/
> driver ... geez louis!

John, the new linux servers boot from the LVM, not directly from the disk device. This is what /etc/fstab looks like on a OL 6.3 server:

[oracle_at_oradb ~]$ less /etc/fstab

#
# /etc/fstab
# Created by anaconda on Fri Jan 11 18:47:40 2013
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more 

info
#

/dev/mapper/vg_oradb-lv_root /                       ext4    
defaults        1 1
UUID=0e891358-55ae-4156-97a8-7b45251d5560 /boot                   ext4    
defaults        1 2
/dev/mapper/vg_oradb-lv_swap swap                    swap    
defaults        0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 
0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 
0
sysfs                   /sys                    sysfs   defaults        0 
0
proc                    /proc                   proc    defaults        0 

0

[oracle_at_oradb ~]$ uname -a
Linux oradb.home.com 2.6.39-300.26.1.el6uek.x86_64 #1 SMP Thu Jan 3 18:31:05 PST 2013 x86_64 x86_64 x86_64 GNU/Linux [oracle_at_oradb ~]$ cat /etc/redhat-release Red Hat Enterprise Linux Server release 6.3 (Santiago)

Here is what the partition layout looks like: [root_at_oradb oracle]# fdisk /dev/sda

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to

         switch off the mode (command 'c') and change display units to
         sectors (command 'u').

Command (m for help): p

Disk /dev/sda: 34.4 GB, 34359738368 bytes 255 heads, 63 sectors/track, 4177 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00009cf3

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          64      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2              64        4178    33041408   8e  Linux LVM

As you can see, /dev/sda1 is the boot device, as denoted by the asterisk in fdisk output:

[root_at_oradb oracle]# mount |grep boot /dev/sda1 on /boot type ext4 (rw)

[root_at_oradb oracle]# df -h /boot

Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             485M  119M  341M  26% /boot

[root_at_oradb oracle]#

Root is mounted on a LVM device. There is a reason for that: you can add physical devices to the logical volume and extend the file system. Install system-config-lvm and you will find great joy and peacefulness in LVM administration, maybe even nirvana.

-- 
Mladen Gogala
The Oracle Whisperer
http://mgogala.byethost5.com

Received on Sun Jan 20 2013 - 03:59:17 CET