Glossary:
- md: multiple devices
| command | description |
|---|---|
cat /proc/mdstat |
show status of all raids |
mdadm --detail /dev/md0 |
detailed status of raid md0 |
mdadm --create /dev/md0 -n2 -l1 /dev/sda1 /dev/sdb1 |
new raid /dev/md0 with 2 disks, raid level 1 on /dev/sda1 and /dev/sda2 |
mdadm --fail /dev/md0 /dev/sda1 ; mdadm --remove /dev/md0 /dev/sda1 |
remove /dev/sda1 from /dev/md0 |
mdadm --add /dev/md0 /dev/sda1 |
add /dev/sda1 to /dev/md0 |
mdadm --grow /dev/md0 -n3 |
use 3 disks in raid /dev/md0 (e.g. add an additional disk, so a damaged drive can be removed later-on) |
mdadm --assemble /dev/md0 |
Assemble /dev/md0 (e.g. when running live system) |
mdadm --detail --scan >> /etc/mdadm/mdadm.conf |
Update list of arrays in /etc/mdadm/mdadm.conf ; you should remove old list by hand first! |
mdadm --examine /dev/sda1 |
What is this disk / partition? |
sysctl -w dev.raid.speed_limit_min=10000 |
Set minimum raid rebuilding speed to 10000 kiB/s (default 1000) |
sfdisk -d /dev/sda | sfdisk /dev/sdb |
Copy partition table from sda to sdb |
- To boot a machine even with a degraded array, modify
/etc/initramfs-tools/conf.d/mdadmand runupdate-initramfs -c -kall(Use with caution!)
Glossary:
- pv: physical device (e.g.
/dev/md0or/dev/sda1) - vg: volume group (consists of 1 or more pvs, contains lvs); has a name (e.g.
lvm) - lv: logical volume (has a name which defines its path, e.g.
/dev/lvm/rootwhich equalsdev/mapper/lvm-root)
| command | description |
|---|---|
pvcreate /dev/md0 |
initializes /dev/md0 as phys device for a volume group |
vgcreate lvm /dev/md0 |
create volume group lvm with phys device /dev/md0 |
lvcreate -L30G -nroot lvm ; mkfs.ext4 /dev/lvm/root |
create logical volume root, sized 30G in volume group lvm; format with ext4 |
lvextend -L60G -nroot lvm ; resize2fs /dev/lvm/root |
extend /dev/lvm/root to 60G; also resize file system to new size |
pvs, vgs, lvs |
show short info about pv, vg and lv |
pvdisplay, vgdisplay, lvdisplay |
show long info |
pvscan /dev/md0 |
scan disks for physical volumes (e.g. when running live system) |
vgextend lvm /dev/md1 |
add phys device /dev/md1 to volume group lvm (need pvcreate first!) |
pvmove /dev/md0 ; vgreduce lvm /dev/md0 |
move all logical volumes from /dev/md0 and remove phys device from volume group |
parted
mklabel gpt
unit s
mkpart bios 64s 2047s
set 1 bios_grub on
mkpart NAME 2048s [end]