How To Set Up Software RAID1 On A Running LVM System (Incl. GRUB Configuration) (Debian Lenny) - Page 3
On this page
6 Preparing GRUB
Afterwards we must install the GRUB bootloader on the second hard drive /dev/sdb:
grub
On the GRUB shell, type in the following commands:
root (hd0,0)
grub> root (hd0,0)
Filesystem type is ext2fs, partition type 0x83
grub>
setup (hd0)
grub> setup (hd0)
Checking if "/boot/grub/stage1" exists... no
Checking if "/grub/stage1" exists... yes
Checking if "/grub/stage2" exists... yes
Checking if "/grub/e2fs_stage1_5" exists... yes
Running "embed /grub/e2fs_stage1_5 (hd0)"... 17 sectors are embedded.
succeeded
Running "install /grub/stage1 (hd0) (hd0)1+17 p (hd0,0)/grub/stage2 /grub/menu.lst"... succeeded
Done.
grub>
root (hd1,0)
grub> root (hd1,0)
Filesystem type is ext2fs, partition type 0xfd
grub>
setup (hd1)
grub> setup (hd1)
Checking if "/boot/grub/stage1" exists... no
Checking if "/grub/stage1" exists... yes
Checking if "/grub/stage2" exists... yes
Checking if "/grub/e2fs_stage1_5" exists... yes
Running "embed /grub/e2fs_stage1_5 (hd1)"... 17 sectors are embedded.
succeeded
Running "install /grub/stage1 (hd1) (hd1)1+17 p (hd1,0)/grub/stage2 /grub/menu.lst"... succeeded
Done.
grub>
quit
Now, back on the normal shell, we reboot the system and hope that it boots ok from our RAID arrays:
reboot
7 Preparing /dev/sda
If all goes well, you should now find /dev/md0 in the output of
df -h
server1:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/debian-root
4.2G 748M 3.2G 19% /
tmpfs 126M 0 126M 0% /lib/init/rw
udev 10M 108K 9.9M 2% /dev
tmpfs 126M 0 126M 0% /dev/shm
/dev/md0 236M 32M 192M 15% /boot
server1:~#
The output of
cat /proc/mdstat
should be as follows:
server1:~# cat /proc/mdstat
Personalities : [raid1]
md1 : active raid1 sda5[0] sdb5[1]
4988032 blocks [2/2] [UU]
md0 : active raid1 sdb1[1]
248896 blocks [2/1] [_U]
unused devices: <none>
server1:~#
The outputs of pvdisplay, vgdisplay, and lvdisplay should be as follows:
pvdisplay
server1:~# pvdisplay
--- Physical volume ---
PV Name /dev/md1
VG Name debian
PV Size 4.76 GB / not usable 3.12 MB
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 1217
Free PE 0
Allocated PE 1217
PV UUID rwRQ4h-Cxii-coUC-ibA0-2tV0-umae-3XC083
server1:~#
vgdisplay
server1:~# vgdisplay
--- Volume group ---
VG Name debian
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 9
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size 4.75 GB
PE Size 4.00 MB
Total PE 1217
Alloc PE / Size 1217 / 4.75 GB
Free PE / Size 0 / 0
VG UUID 4UfyCV-s32P-uZ5R-asRH-9Jjg-pkF6-d5wi32
server1:~#
lvdisplay
server1:~# lvdisplay
--- Logical volume ---
LV Name /dev/debian/root
VG Name debian
LV UUID N58aS0-n1uV-32gb-S51m-kP75-sfA5-38SMVo
LV Write Access read/write
LV Status available
# open 1
LV Size 4.19 GB
Current LE 1072
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Name /dev/debian/swap_1
VG Name debian
LV UUID IGWTnc-Zgmr-pKW8-Jcp6-URYF-2j2D-Ile6kQ
LV Write Access read/write
LV Status available
# open 2
LV Size 580.00 MB
Current LE 145
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
server1:~#
Now we must change the partition type of /dev/sda1 to Linux raid autodetect as well:
fdisk /dev/sda
server1:~# fdisk /dev/sda
Command (m for help): <-- t
Partition number (1-5): <-- 1
Hex code (type L to list codes): <-- fd
Changed system type of partition 1 to fd (Linux raid autodetect)
Command (m for help): <-- w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.
server1:~#
Now we can add /dev/sda1 to the /dev/md0 RAID array:
mdadm --add /dev/md0 /dev/sda1
Now take a look at
cat /proc/mdstat
server1:~# cat /proc/mdstat
Personalities : [raid1]
md1 : active raid1 sda5[0] sdb5[1]
4988032 blocks [2/2] [UU]
md0 : active raid1 sda1[0] sdb1[1]
248896 blocks [2/2] [UU]
unused devices: <none>
server1:~#
Then adjust /etc/mdadm/mdadm.conf to the new situation:
cp /etc/mdadm/mdadm.conf_orig /etc/mdadm/mdadm.conf
mdadm --examine --scan >> /etc/mdadm/mdadm.conf
/etc/mdadm/mdadm.conf should now look something like this:
cat /etc/mdadm/mdadm.conf
# mdadm.conf # # Please refer to mdadm.conf(5) for information about this file. # # by default, scan all partitions (/proc/partitions) for MD superblocks. # alternatively, specify devices to scan, using wildcards if desired. DEVICE partitions # auto-create devices with Debian standard permissions CREATE owner=root group=disk mode=0660 auto=yes # automatically tag new arrays as belonging to the local system HOMEHOST <system> # instruct the monitoring daemon where to send mail alerts MAILADDR root # definitions of existing MD arrays # This file was auto-generated on Wed, 19 Aug 2009 16:13:09 +0200 # by mkconf $Id$ ARRAY /dev/md0 level=raid1 num-devices=2 UUID=00d834dc:29cbe6c1:325ecf68:79913751 ARRAY /dev/md1 level=raid1 num-devices=2 UUID=8ce23a63:d17dd58b:325ecf68:79913751 |
Reboot the system:
reboot
It should boot without problems.
That's it - you've successfully set up software RAID1 on your running LVM system!
