Make Diferences between rescue in LVM and BTRF File System

Why this change is needed:

With the new default system in BTRF as Defautl for new instalation
this procedure needs updated.

What this change accomplishes:

. Reflect the diferences between rescue a system in a LVM/BTRF file System.
. Remove Sequence Number Warninig in a debug-dracut-problems.adoc

fix ticket: #316

Note: Please don't push .adoc with Warning Messages is quite anoying
This commit is contained in:
Héctor Louzao 2021-01-09 12:33:12 +01:00 committed by pbokoc
parent 8811afe682
commit f2a2581b85
2 changed files with 63 additions and 32 deletions

View file

@ -1,9 +1,14 @@
[[restoring-bootloader-using-live-disk]]
= Restoring the bootloader using the Live disk.
Sometimes, especially after a secondary operating systems has been installed, the master boot record gets damaged which then prevents the original Linux system from booting.
Sometimes, especially after a secondary operating systems has been installed,
the master boot record gets damaged which then prevents the original Linux system
from booting.
If this happens, it is necessary to reinstall *GRUB2* to recreate the original settings. The process not only discovers all installed operating systems, but usually adds them to the *GRUB2* configuration files, so they will all become bootable by *GRUB2*.
If this happens, it is necessary to reinstall *GRUB2* to recreate the original
settings. The process not only discovers all installed operating systems, but
usually adds them to the *GRUB2* configuration files, so they will all become
bootable by *GRUB2*.
.Before you start
@ -18,18 +23,22 @@ If this happens, it is necessary to reinstall *GRUB2* to recreate the original s
. Open the terminal.
. Examine the partition layout and identify the `boot` and the `root` partition.
+
----
# fdisk -l
----
+
If you are using the default Fedora layout, there will be one `/dev/sda1` partition that holds the `/boot` directory and one `/dev/mapper/fedora-root` that holds the root file system.
== For Default Instalation in LVM.
. Create the mount point for the root partition.
+
----
# mkdir -p /mnt/root
----
----
If you are using the default Fedora layout, there will be one `/dev/sda1`
partition that holds the `/boot` directory and one `/dev/mapper/fedora-root`
that holds the root file system.
. Mount the root partition on the mount point.
+
@ -38,12 +47,33 @@ If you are using the default Fedora layout, there will be one `/dev/sda1` partit
----
. Mount the boot partition in the `boot` directory of the filesystem that you have mounted in the previous step.
+
----
# mount /dev/sda1 /mnt/root/boot/
----
. Mount system processes and devices into the root filesystem in `/mnt/root`.
== For default Instalation in BTRF
. Create the mount point for the root partition.
----
# mkdir -p /mnt/
----
If you are using the default Fedora layout, there will be one `/dev/sda1`
partition that holds the `/boot` directory and one `/dev/sda2` that holds the root file system.
----
# mount /dev/sda2/ /mnt
# mount /dev/sda1 /mnt/root/boot
----
IMPORTANT: Home Partition is mounted automatically under `/mnt/home`
== Continue with the follow Procedure.
. Mount system processes and devices into the root filesystem in
`/mnt/root`.
+
----
# mount -o bind /dev /mnt/root/dev
@ -58,7 +88,8 @@ If you are using the default Fedora layout, there will be one `/dev/sda1` partit
# chroot /mnt/root
----
. Regenerate the *GRUB2* configuration file and reinstall the bootloader into the MBR, as described in xref:adding-other-operating-systems-grub2[Adding other operating systems to the *GRUB2* menu].
. Regenerate the *GRUB2* configuration file and reinstall the bootloader
into the MBR, as described in xref:adding-other-operating-systems-grub2[Adding other operating systems to the *GRUB2* menu].
. Exit this temporary root filesystem.
+
@ -67,7 +98,7 @@ $ exit
----
. Your bootloader should be now restored. Reboot your computer to boot into your normal system.
+
----
# systemctl reboot
----

View file

@ -16,12 +16,12 @@ uncompressed, with MIME type set as text/plain.
[[identifying-your-problem-area]]
== Identifying your problem area
1. Remove `rhgb` and `quiet` from the kernel command line
2. Add `rd.shell` to the kernel command line. This will present a shell
. Remove `rhgb` and `quiet` from the kernel command line
. Add `rd.shell` to the kernel command line. This will present a shell
in case dracut is unable to locate your root device
3. Add `rd.shell rd.debug log_buf_len=1M` to the kernel command line so
. Add `rd.shell rd.debug log_buf_len=1M` to the kernel command line so
that dracut shell commands are printed as they are executed
4. Inspect the system logs:
. Inspect the system logs:
....
# less /run/initramfs/rdsosreport.txt
# journalctl -a
@ -94,20 +94,20 @@ console connection to record boot messages. To enable serial console
output for both the kernel and the bootloader, follow the procedure
below.
1. Open the file `/etc/grub.conf` for editing. Below the line _timeout=5_, add the following:
. Open the file `/etc/grub.conf` for editing. Below the line _timeout=5_, add the following:
+
....
serial --unit=0 --speed=9600
terminal --timeout=5 serial console
....
2. Also in `/etc/grub.conf`, add the following boot arguments to the _kernel_ line:
. Also in `/etc/grub.conf`, add the following boot arguments to the _kernel_ line:
+
....
console=tty0 console=ttyS0,9600
....
3. When finished, `/etc/grub.conf` should look similar to the example below:
. When finished, `/etc/grub.conf` should look similar to the example below:
....
default=0
@ -130,9 +130,9 @@ http://www.faqs.org/docs/Linux-HOWTO/Remote-Serial-Console-HOWTO.html#CONFIGURE-
Dracut offers a shell for interactive debugging in the event dracut
fails to locate your root filesystem. To enable the shell:
1. Add the boot parameter `rd.shell` to your bootloader configuration
. Add the boot parameter `rd.shell` to your bootloader configuration
file (e.g. `/etc/grub/conf`)
2. Remove the boot arguments `rhgb` and `quiet`
. Remove the boot arguments `rhgb` and `quiet`
A sample `/etc/grub.conf` bootloader configuration file is listed below:
@ -179,8 +179,8 @@ The exact method for locating and preparing will vary. However, to
continue with a successful boot, the objective is to locate your root
volume and create a symlink `/dev/root` which points to the file system. For example, the following example demonstrates accessing and booting a root volume that is an encrypted LVM Logical volume.
1. Inspect your partitions using `parted`:
. Inspect your partitions using `parted`:
+
....
# parted /dev/sda -s p
Model: ATA HTS541060G9AT00 (scsi)
@ -193,16 +193,16 @@ Number Start End Size Type File system Flags
2 10.8GB 55.6GB 44.7GB logical lvm
....
2. You recall that your root volume was a LVM logical volume. Scan and
. You recall that your root volume was a LVM logical volume. Scan and
activate any logical volumes:
+
....
# lvm vgscan
# lvm vgchange -ay
....
3. You should see any logical volumes now using the command `blkid`:
. You should see any logical volumes now using the command `blkid`:
+
....
# blkid
/dev/sda1: UUID="3de247f3-5de4-4a44-afc5-1fe179750cf7" TYPE="ext4"
@ -212,12 +212,12 @@ Number Start End Size Type File system Flags
/dev/mapper/linux-swap: UUID="47b4d329-975c-4c08-b218-f9c9bf3635f1" TYPE="swap"
....
4. From the output above, you recall that your root volume exists on an
. From the output above, you recall that your root volume exists on an
encrypted block device. Following the guidance disk encryption guidance
from the
http://docs.fedoraproject.org/install-guide/f%7B%7BFedoraVersion%7D%7D/en-US/html/apcs04s04.html[
Installation Guide], you unlock your encrypted root volume.
+
....
UUID=$(cryptsetup luksUUID /dev/mapper/linux-root)
cryptsetup luksOpen /dev/mapper/linux-root luks-$UUID
@ -225,13 +225,13 @@ Enter passphrase for /dev/mapper/linux-root:
Key slot 0 unlocked.
....
5. Next, make a symbolic link to the unlocked root volume
. Next, make a symbolic link to the unlocked root volume
+
....
ln -s /dev/mapper/luks-$UUID /dev/root
....
6. With the root volume available, you may continue booting the system
. With the root volume available, you may continue booting the system
by exiting the dracut shell
....