Fun with LVM

Jozef

Basics

apt-get install lvm2 dmsetup

• pv - physical volume
• vg - volume group
• lv - logical volume

PV

Physical volume

• pvcreate /dev/hdb
• pvscan -v -u
• pvmove -v /dev/hdb

VG

Volume group

• vgcreate vg00 /dev/hdb
• vgdisplay -v
• vgextend vg00 /dev/hdd
• vgreduce vg00 /dev/hdb
• why more than one vg?

LV

Logical volume

• lvcreate -n test1 -L 200M vg00
• mkfs.ext3 -m0 /dev/mapper/vg00-test1
• mount /dev/mapper/vg00-test1 /mnt
• df -h
• vgdisplay -v
• lvextend -L 400M vg00/test1
• resize2fs /dev/mapper/vg00-test1 400M
• # lvreduce -L 150M vg00/test1
• # lvremove vg00/test1

migrating

stop using /dev/hdd

• vgdisplay -v
• vgextend vg00 /dev/hdb
• pvmove -v /dev/hdd
• vgreduce vg00 /dev/hdd
• vgdisplay -v
• badblocks -s -v -w /dev/hdd

physical?

what can be pv

• /dev/hdb
• /dev/hdb2
• /dev/md0
• iSCSI
• any other block device

it's always fun with hotswap

And that's it...

Questions?