I got myself a new Server on which I’m going to install Gentoo with systemd. The Serverspecs are:

CPU1: Intel(R) Xeon(R) CPU E3-1245 V2 @ 3.40GHz (Cores 8)
Memory:  15960 MB
Disk /dev/sda: 3000 GB (=> 2794 GiB) doesn't contain a valid partition table
Disk /dev/sdb: 3000 GB (=> 2794 GiB) doesn't contain a valid partition table
Total capacity 5589 GiB with 2 Disks

Install preparations

But lets get down to business. There are a couple of decisions that have to be made before the installation of the operating system. First is the partioning of the harddrives. As one can see from the code fragment above, the server has 2 x 3 TB disk space. Since the main purpose of the server is to host customer websites and databases a hugh junk of the disk will be used for datastorage. The other decision is about the bootloader, which is decided by wether it is a legacy BIOS or an EFI system.

BIOS or EFI

To determine if the system has a legacy BIOS or an EFI bootloader an article at askubuntu.com suggests to check /proc/firmware/efi which tells if the system is booted as EFI. In my case this was not the case. It was also mentioned to check the kernel bootlog, dmesg, if there are any hints on a EFI system. But from expirience with previous servers from Hetzner it seem the case that their systems are all legacy boot systems, which is fine because there are not any important feature differences for a server system.

Partitioning and disk layout

The server sadly has no hardware RAID controller, but since it has two disk drives with each having enough space, I decided to go with a mirrored software RAID 1. For the data patition an LVM will be used so that I’m a little bit more flexible in allocating the space. The patitions will be like this:

1. (EF02) Partition for GRUB Bios files
2. (FD00) 500MB ext2 /boot
3. (8200) SWAP 16GB
4. (FD00) 500GB ext4 /
5. (FD00) LVM 2,34TB
   1. /customers 1,5TB ext4
   2. /usr/portage 50GB ext2
   3. /usr/portage/distfiles 100GB ext2

# parted -a optimal /dev/sda
(parted) mklabel gpt
(parted) unit MiB
(parted) mkpart primary 2 100
(parted) set 1 bios_grub on
(parted) mkpart primary 512 1024
(parted) mkpart primary linux-swap(v1) 1024 17408
(parted) mkpart primary 17408 529408
(parted) mkpart primary 529408 -1
(parted) set 2 raid on
(parted) set 4 raid on
(parted) set 5 raid on
(parted) p
Model: ATA ST33000650NS (scsi)
Disk /dev/sda: 2861588MiB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start      End         Size        File system     Name                 Flags
 1      1.00MiB    101MiB      100MiB                      BIOS boot partition  bios_grub
 2      512MiB     1024MiB     512MiB      ext2            primary              raid
 3      1024MiB    17408MiB    16384MiB    linux-swap(v1)  primary
 4      17408MiB   529408MiB   512000MiB   ext4            primary              raid
 5      529408MiB  2861588MiB  2332180MiB                  primary              raid

Now that the partitions on sda are created, the patition table will be mirrored to sdb using sgdisk and then a new GUID will be generated for sdb.

sgdisk -R /dev/sdb /dev/sda
sgdisk -G /dev/sdb

RAID initialization

So let’s initialize the RAID. For /boot and / I use the metadata 0.9, since otherwise I would need an initramfs, which I’m not familiar with.

mdadm --create /dev/md0 --level=1 --raid-devices=2 --metadata=0.90 /dev/sda2 /dev/sdb2
mdadm --create /dev/md1 --level=1 --raid-devices=2 --metadata=0.90 /dev/sda4 /dev/sdb4
mdadm --create /dev/md2 --level=1 --raid-devices=2 /dev/sda5 /dev/sdb5

This will take a while due to the size of the disk drives. The current progress can be seen by issuing the following command `cat /proc/mdstat`

LVM Partitions

Next is the preparation of the newly created md3 RAID 1 for LVM. First a physical volume is created on md3 and then a volume group called vg. This volume group then holds the logical volumes.

pvcreate /dev/md2
vgcreate vg /dev/md2
lvcreate -L10G -nportage vg
lvcreate -L50G -ndistfiles vg
lvcreate -L1T -ncustomer vg

Filesystems

The boot partition will have a simple ext2, where as all other partition will have an ext4 filesystem.

mkfs.ext2 /dev/md0
mkfs.ext4 /dev/md1
mkswap /dev/sda2 && mkswap /dev/sdb2
swapon -p 1 /dev/sda2 && swapon -p 1 /dev/sdb2
mkfs.ext2 -b 1024 -N 200000 /dev/vg/portage
mkfs.ext2 -b 4096 -T largefile /dev/vg/distfiles
mkfs.ext4 /dev/vg/customer

Now the preparations for the installation are done and I will post the install process in another post.