configuring RAID1 after installation
 

Hi all,

I just learned about mirroring of disk using RAID1 in RHEL. I went through the steps to configure my disks. But I am bit confused about how to start with. Actually I have one device /dev/mapper/rhel-home mounted on home. I want to mirror this device with /dev/sdc. I would really appreciate any help.

Here is my df -h and fdisk -l output
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/rhel-root 50G 5.7G 45G 12% /
devtmpfs 32G 0 32G 0% /dev
tmpfs 32G 764K 32G 1% /dev/shm
tmpfs 32G 9.0M 32G 1% /run
tmpfs 32G 0 32G 0% /sys/fs/cgroup
/dev/mapper/rhel-home 3.6T 193M 3.6T 1% /home
/dev/sda3 494M 116M 379M 24% /boot
/dev/sda1 496M 95M 402M 19% /boot/efi


Disk /dev/sdb: 4000.8 GB, 4000787030016 bytes, 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/sda: 4000.8 GB, 4000787030016 bytes, 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: dos
Disk identifier: 0xe7d96bb9

Device Boot Start End Blocks Id System
/dev/sda1 1 4294967295 2147483647+ ee GPT
Partition 1 does not start on physical sector boundary.

Disk /dev/sdc: 4000.8 GB, 4000787030016 bytes, 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/mapper/rhel-root: 53.7 GB, 53687091200 bytes, 104857600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/mapper/rhel-swap: 33.8 GB, 33764147200 bytes, 65945600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/mapper/rhel-home: 3905.2 GB, 3905249345536 bytes, 7627440128 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

If you went through the steps to configure your disk, I would guess that /dev/mapper/rhel-home is already a RAID 1 device, perhaps using sdb and sdc.

Can you show us the output of lsblk, vgs and lvs? This should give us more clarity about rhel-home.

Hi,

Thanks for reply,

Here are the outputs of lsblk, vgs and lvs


NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 3.7T 0 disk
├─sda1 8:1 0 500M 0 part /boot/efi
├─sda2 8:2 0 40M 0 part
├─sda3 8:3 0 500M 0 part /boot
├─sda4 8:4 0 6G 0 part
└─sda5 8:5 0 3.6T 0 part
├─rhel-root 253:0 0 50G 0 lvm /
├─rhel-swap 253:1 0 31.5G 0 lvm [SWAP]
└─rhel-home 253:2 0 3.6T 0 lvm /home
sdb 8:16 0 3.7T 0 disk
sdc 8:32 0 3.7T 0 disk
sr0 11:0 1 1024M 0 rom


VG #PV #LV #SN Attr VSize VFree
rhel 1 3 0 wz--n- 3.63t 0


home rhel -wi-ao---- 3.55t
root rhel -wi-ao---- 50.00g
swap rhel -wi-ao---- 31.45g