Arch Linux

stueja

Member

Registered: 2015-10-18

Posts: 47

[SOLVED] Fresh re-install with (not: on) unencrypted LVM on md-RAID1

Hello everyone,

I have a system with one system disk and two separate disks in an unencrypted LVM on an md-RAID 1. (Config below). I would like to re-install Arch Linux from scratch and still be able to use the RAID after reinstallation. I am unsure where to begin.

Is that just a matter of re-installing Arch Linux and scanning for the RAID like:

sudo pacman -S mdadm
sudo mdadm --assemble --scan
sudo pvscan
sudo vgchange -ay vgRAID

?

Current configuration:
lsblk:

NAME                MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda                   8:0    0 232.9G  0 disk  
|-sda1                8:1    0   200M  0 part  /boot
|-sda2                8:2    0    80G  0 part  /
|-sda3                8:3    0    15G  0 part  
|-sda4                8:4    0     1K  0 part  
|-sda5                8:5    0    15G  0 part  /var
|-sda6                8:6    0    15G  0 part  [SWAP]
`-sda7                8:7    0 107.7G  0 part  /home
sdb                   8:16   0   5.5T  0 disk  
`-sdb1                8:17   0   5.5T  0 part  
  `-md0               9:0    0   5.5T  0 raid1 
    `-vgRAID-lvdata 254:0    0   5.5T  0 lvm   /media/data
sdc                   8:32   0   5.5T  0 disk  
`-sdc1                8:33   0   5.5T  0 part  
  `-md0               9:0    0   5.5T  0 raid1 
    `-vgRAID-lvdata 254:0    0   5.5T  0 lvm   /media/data

mdadm --export --detail /dev/md0:

MD_LEVEL=raid1
MD_DEVICES=2
MD_METADATA=1.2
MD_UUID=79de32fa:613377b2:2db4e8c9:15974d6f
MD_DEVNAME=0
MD_NAME=server:0
MD_DEVICE_sdc1_ROLE=1
MD_DEVICE_sdc1_DEV=/dev/sdc1
MD_DEVICE_sdb1_ROLE=0
MD_DEVICE_sdb1_DEV=/dev/sdb1

vgcfgbackup -f vgbackup.txt

# Generated by LVM2 version 2.02.183(2) (2018-12-07): Fri Mar  8 23:37:20 2019

contents = "Text Format Volume Group"
version = 1

description = "vgcfgbackup -f vgbackup.txt"

creation_host = "server"	# Linux server 4.20.13-arch1-1-ARCH #1 SMP PREEMPT Wed Feb 27 19:10:28 UTC 2019 x86_64
creation_time = 1552084640	# Fri Mar  8 23:37:20 2019

vgRAID {
	id = "8NJorl-UwVW-1337-o6p6-ZP6H-JNiE-gRj5no"
	seqno = 2
	format = "lvm2"			# informational
	status = ["RESIZEABLE", "READ", "WRITE"]
	flags = []
	extent_size = 8192		# 4 Megabytes
	max_lv = 0
	max_pv = 0
	metadata_copies = 0

	physical_volumes {

		pv0 {
			id = "iPOp35-h2qB-1337-GE5J-kmsY-mX63-6UtOMG"
			device = "/dev/md0"	# Hint only

			status = ["ALLOCATABLE"]
			flags = []
			dev_size = 11720780928	# 5.45791 Terabytes
			pe_start = 2048
			pe_count = 1430759	# 5.45791 Terabytes
		}
	}

	logical_volumes {

		lvdata {
			id = "BbCuHm-Jeto-IP07-Wpu3-uHyD-60QH-21VNdS"
			status = ["READ", "WRITE", "VISIBLE"]
			flags = []
			creation_time = 1518990601	# 2018-02-18 22:50:01 +0100
			creation_host = "server"
			segment_count = 1

			segment1 {
				start_extent = 0
				extent_count = 1430759	# 5.45791 Terabytes

				type = "striped"
				stripe_count = 1	# linear

				stripes = [
					"pv0", 0
				]
			}
		}
	}

}

Last edited by stueja (2019-03-10 15:10:06)

stueja

Member

Registered: 2015-10-18

Posts: 47

Re: [SOLVED] Fresh re-install with (not: on) unencrypted LVM on md-RAID1

Ya, that was basically it.
Reinstalled from scatch, then ran

[jan@server jan]# sudo mdadm --detail --scan >> /etc/mdadm.conf 
[jan@server jan]# sudo mdadm --assemble --scan
[jan@server jan]# sudo pvscan
  PV /dev/md0   VG vgRAID          lvm2 [<5.46 TiB / 0    free]
  Total: 1 [<5.46 TiB] / in use: 1 [<5.46 TiB] / in no VG: 0 [0   ]
[jan@server jan]# sudo vgchange -ay vgRAID
  1 logical volume(s) in volume group "vgRAID" now active
[jan@server jan]# sudo mount /dev/vgRAID/lvdata /media/data/
[jan@server jan]# lsblk
NAME                MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda                   8:0    0 232.9G  0 disk  
├─sda1                8:1    0   200M  0 part  /boot
├─sda2                8:2    0     8G  0 part  
└─sda3                8:3    0 224.7G  0 part  /
sdb                   8:16   0   5.5T  0 disk  
└─sdb1                8:17   0   5.5T  0 part  
  └─md0               9:0    0   5.5T  0 raid1 
    └─vgRAID-lvdata 253:0    0   5.5T  0 lvm   /media/data
sdc                   8:32   0   5.5T  0 disk  
└─sdc1                8:33   0   5.5T  0 part  
  └─md0               9:0    0   5.5T  0 raid1 
    └─vgRAID-lvdata 253:0    0   5.5T  0 lvm   /media/data

May my answer help future readers if my question didn't help in the present.

Last edited by stueja (2019-03-10 15:11:23)