Replace Oracle Cloud Linux with Arch Linux ARM remotely

convert2arch_arm.sh

[09/23/2023]

Refs:
1. http://os.archlinuxarm.org/os/ArchLinuxARM-aarch64-latest.tar.gz
2. https://dl-cdn.alpinelinux.org/alpine/v3.18/releases/aarch64/alpine-virt-3.18.0-aarch64.iso
3. https://wiki.alpinelinux.org/wiki/Replacing_non-Alpine_Linux_with_Alpine_remotely
4. https://wiki.archlinux.org/index.php/installation_guide#Configure_the_system
5. https://archlinuxarm.org/platforms/armv8/generic

See also:
1. Convert to Debian   https://gist.github.com/zengxinhui/ee0ad6b7c7f99e2ead6cd0d2bd6641fd
2. Convert to arch x64 https://gist.github.com/zengxinhui/f328fdce54f5039689ee3aa4e91fc805
3. Convert to arch arm https://gist.github.com/zengxinhui/01afb43b8d663a4232a42ee9858be45e

Requirement:
  Console access.
  
# Prepare alpine linux, which can be configured to run from ram only.
# Alpine is leveraged to do the conversion.
# In any linux(ubuntu/debian/arch tested) become root first:
sudo su -
cd /tmp && wget https://dl-cdn.alpinelinux.org/alpine/v3.18/releases/aarch64/alpine-virt-3.18.0-aarch64.iso
dd if=alpine-virt-3.18.0-aarch64.iso of=/dev/sda && sync && reboot

# In Alpine with console:
# [Bring up networking]
ip li set eth0 up
udhcpc eth0
# [Setup SSH, answer RET, yes, RET]
setup-sshd
# [set temp password]
passwd
# [At this point it's easier to use SSH to copy & paste]

# [Per Ref #3]
mkdir /media/setup
cp -a /media/sda/* /media/setup
mkdir /lib/setup
cp -a /.modloop/* /lib/setup
/etc/init.d/modloop stop
umount /dev/sda
mv /media/setup/* /media/sda/
mv /lib/setup/* /.modloop/

# [Setup apk and bring in pacman]
setup-apkrepos
# [enable community]
vi /etc/apk/repositories

apk update
apk add dosfstools e2fsprogs findmnt pacman arch-install-scripts

# [Disk partitioning & mounting]
# (use gpt table, set esp partition 15 size 256M), set root partition 1 size remaining)
# g, n, 15, RET, +256m, t, 1, n, RET, RET, RET, p, w
fdisk /dev/sda

ls /dev/sda*
# if sda1 or sda15 is missing, do "/etc/init.d/devfs restart"

mkfs.vfat /dev/sda15
mkfs.ext4 /dev/sda1

mount -t ext4 /dev/sda1 /mnt
mkdir /mnt/boot
mount /dev/sda15 /mnt/boot

cd /mnt && wget http://os.archlinuxarm.org/os/ArchLinuxARM-aarch64-latest.tar.gz
bsdtar -xpf /mnt/ArchLinuxARM-aarch64-latest.tar.gz -C /mnt
genfstab -U /mnt >> /mnt/etc/fstab

cd /; arch-chroot /mnt/
# This is your arch root password. Choose carefully and remember it
# do the same for user `alarm` if you prefer to use that account and lots of `sudo`
passwd
cat > ~/.ssh/authorized_keys << EOF
<your key here>
EOF

cat > /etc/resolv.conf << EOF
nameserver 1.1.1.1
nameserver 4.2.2.2
nameserver 8.8.8.8
EOF

pacman-key --init
pacman-key --populate archlinuxarm
pacman --noconfirm -Syu grub efibootmgr vi

# [EFI boot]
grub-install --efi-directory=/boot --bootloader-id=GRUB
vi /etc/default/grub
# Better console. Comparison below:
# GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3 quiet"
# GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3 console=ttyS0,115200"
# Or use perl/sed to replace
#   perl -pi.bak -e "s/quiet/console=ttyS0,115200/" /etc/default/grub
#   sed   -i.bak -e "s/quiet/console=ttyS0,115200/" /etc/default/grub
grub-mkconfig -o /boot/grub/grub.cfg
exit
reboot

It would be nice to mention to switch to root user in original host OS

it would also be nice to note down that the alpine account is root for login from the Console.

And like e-minguez said it would be nice to mention that to mention how to gain root access in alarm.

Thanks a lot, this saved me a lot of time!

I've also saved it to my own repo with some small changes - https://gitlab.com/C0rn3j/arch/-/blob/master/OracleCloudARM.md

I'm missing something as I don't see /dev/sda1 after doing fdisk partitioning steps... anyone ran into the same issue?

localhost:~# fdisk /dev/sda

Welcome to fdisk (util-linux 2.38.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

GPT PMBR size mismatch (105191 != 97677311) will be corrected by write.
The backup GPT table is not on the end of the device. This problem will be corrected by write.
The device contains 'iso9660' signature and it will be removed by a write command. See fdisk(8) man page and --wipe option for more details.

Command (m for help): g

Created a new GPT disklabel (GUID: 3CC9C60C-EA66-3341-B4AF-DE608E36B04D).
The device contains 'iso9660' signature and it will be removed by a write command. See fdisk(8) man page and --wipe option for more details.

Command (m for help): p

Disk /dev/sda: 46.58 GiB, 50010783744 bytes, 97677312 sectors
Disk model: BlockVolume     
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 1048576 bytes
Disklabel type: gpt
Disk identifier: 3CC9C60C-EA66-3341-B4AF-DE608E36B04D

Command (m for help): n
Partition number (1-128, default 1): 15
First sector (2048-97677278, default 2048): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-97677278, default 97675263): +512M

Created a new partition 15 of type 'Linux filesystem' and of size 512 MiB.

Command (m for help): t
Selected partition 15
Partition type or alias (type L to list all): 1
Changed type of partition 'Linux filesystem' to 'EFI System'.

Command (m for help): n
Partition number (1-14,16-128, default 1): 
First sector (1050624-97677278, default 1050624): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (1050624-97677278, default 97675263): 

Created a new partition 1 of type 'Linux filesystem' and of size 46.1 GiB.

Command (m for help): p
Disk /dev/sda: 46.58 GiB, 50010783744 bytes, 97677312 sectors
Disk model: BlockVolume     
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 1048576 bytes
Disklabel type: gpt
Disk identifier: 3CC9C60C-EA66-3341-B4AF-DE608E36B04D

Device       Start      End  Sectors  Size Type
/dev/sda1  1050624 97675263 96624640 46.1G Linux filesystem
/dev/sda15    2048  1050623  1048576  512M EFI System

Partition table entries are not in disk order.

Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

localhost:~# ls /dev
block            loop-control  sda15   tty19  tty34  tty5   tty8     vcsa2
bsg              loop0         shm     tty2   tty35  tty50  tty9     vcsa3
bus              loop1         stderr  tty20  tty36  tty51  ttyAMA0  vcsa4
console          loop2         stdin   tty21  tty37  tty52  ttyS0    vcsa5
cpu_dma_latency  loop3         stdout  tty22  tty38  tty53  ttyS1    vcsa6
disk             loop4         tty     tty23  tty39  tty54  ttyS2    vcsu
dri              loop5         tty0    tty24  tty4   tty55  ttyS3    vcsu1
fb0              loop6         tty1    tty25  tty40  tty56  urandom  vcsu2
fd               loop7         tty10   tty26  tty41  tty57  vcs      vcsu3
full             mem           tty11   tty27  tty42  tty58  vcs1     vcsu4
hidraw0          mqueue        tty12   tty28  tty43  tty59  vcs2     vcsu5
hidraw1          null          tty13   tty29  tty44  tty6   vcs3     vcsu6
hidraw2          ptmx          tty14   tty3   tty45  tty60  vcs4     zero
input            pts           tty15   tty30  tty46  tty61  vcs5
kmsg             random        tty16   tty31  tty47  tty62  vcs6
log              rtc0          tty17   tty32  tty48  tty63  vcsa
loop             sda           tty18   tty33  tty49  tty7   vcsa1
localhost:~# mkfs.ext4  /dev/sda1
mke2fs 1.46.5 (30-Dec-2021)
The file /dev/sda1 does not exist and no size was specified.
localhost:~# 

You manually partition the disk at this step. Until that is done there's no sda1.

The disk is partiioned according to fdisk

Device       Start      End  Sectors  Size Type
/dev/sda1  1050624 97675263 96624640 46.1G Linux filesystem
/dev/sda15    2048  1050623  1048576  512M EFI System

but /dev/sda1 does not show under /dev when doing ls /dev only /dev/sda and /dev/sda15

so for whatever reason, the node device for /dev/sda1 was not present.... fixed it with:

mknod /dev/sda1 b 8 1

Thanks for the instructions.

If anyone runs into the problem of not being able to ssh into the machine after changing CPU count, try going into Oracle's Cloud Console. There, you should find yourself in the EFI Shell as grub couldn't be booted (at least in my case).

Enter map to get the mapping table. First entry should be FS0, so enter FS0: to change directory to the FS0 device. You should now be on the boot partition. You should be able to cd EFI/GRUB, and ls to confirm that there is the grubaa64.efi. Enter grubaa64.efi to boot grub/Arch.

You can now either login through that Console or ssh into your machine and run grub-install --efi-directory=/boot/efi --bootloader-id=GRUB again. It should now reboot as usual.

Not really sure what exactly causes it, some part isn't persistent through CPU count/memory amount changes.

has anyone had luck installing fedora cloud on this?

just a doubt, I have to create an instance with Oracle Linux 8, is that it?

The only change I would make is to switch ext4 to BTRFS + ZSTD

Followed this guide and with a few tiny mods got Arch up and running. I had one or a few reboots in the process.

When I issued poweroff - Arch powered off but the instance said Running in my Oracle account. I stopped the instance, and the next time I tried running it - it wouldn't boot up, no pings, no SSH. The console shows me Shell> only.

Is the intention here that Alpine is running 24/7 and when it stops - your Arch OS is gone or did I just miss a step somewhere and it's an easy recover?

---

Played with it for a while. I can get to the UEFI shell and launch EFI/GRUB/grubaa64.efi directly, but this is not a long-term solution. Right now I have a functioning system but whenever I need to power it up I need to create a serial connection and launch OS manually. I even created /boot/startup.nsh but that didn't help