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RAID

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Vlad edited this page Jul 7, 2020 · 6 revisions

Redundant Array of Independent Disks

Steps

# Check disks
sudo fdisk -l
# OR
sudo lsblk

# Install Ubuntu Packages
sudo apt-get update && sudo apt-get -y install lvm2 mdadm

# Install CentOS packages
sudo yum update -y && sudo yum install -y lvm2 mdadm

# Check block details
sudo mdadm --examine /dev/sd[a-i]1 # or /dev/sd[acde]1

# Create RAID partition on each disk
sudo fdisk /dev/sdb
# > d (delete partitions)
# > n (create partition)
# > t (change partition type; find it with `L`; Linux RAID is 29)
# > w (write changes)

# Examine partitions
sudo mdadm --examine /dev/sd[b-i]

# Create RAID10
sudo mdadm --create /dev/md0 --level=10 --raid-devices=4 /dev/sd[bcde]1

# Create RAID5 (7+1 disks)
sudo mdadm --create /dev/md5 --level=5 --raid-devices=8 /dev/sd[b-i]1

# Check info
sudo mdadm --detail /dev/md0
sudo mdadm --detail /dev/md5

# Watch resync progress
watch -n1 cat /proc/mdstat

# Tune minimum resync speed (bring back to initial value after, which is 1000 so it does not impact performance)
sudo sysctl dev.raid.speed_limit_min # Check value (default is 1000)
sudo sysctl -w dev.raid.speed_limit_min=1000000 # Temporary change value
sudo sysctl -w dev.raid.speed_limit_min=1000 # Restore value

# Update mdadm config on Ubuntu
sudo bash /usr/share/mdadm/mkconf | sudo tee /etc/mdadm/mdadm.conf
# Or 
sudo mdadm --examine --scan | sudo tee -a /etc/mdadm/mdadm.conf
# Update initramfs
sudo update-initramfs -u

# Update mdadm config on CentOS
sudo mdadm --detail --scan --verbose | sudo tee -a /etc/mdadm.conf

# Create LVM Physical Volume (check with pvdisplay)
sudo pvcreate /dev/md0
# Create Volume Group (check with vgdisplay)
sudo vgcreate data_vg /dev/md0
# Create Logical Volumes (check with lvdisplay)
sudo lvcreate -l +100%FREE -n data_lv data_vg
# Create filesystems
sudo mkfs.ext4 /dev/data_vg/data_lv

# Add to fstab
sudo mkdir -p /data
sudo echo '/dev/data_vg/data_lv  /data  ext4  defaults  0 2' | sudo tee -a /etc/fstab

# Mount array
sudo mount -a

References

DOCs

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