Category: General
- Create VG
pvcreate /dev/mapper/... vgcreate vg0 ... lvcreate -L10G -nimagename vg0
- Extend the size of LV
lvextend -L +25GB /dev/vg0/some-disk e2fsck -f /dev/vg0/some-disk resize2fs /dev/vg0/some-disk
- Reduce size of LV
resize2fs /dev/myvg/homevol 524288 lvreduce -L -1G /dev/myvg/homevol
- Add hard disk to lvm
# Format the disk to an ext3 file system by running ‘cfdisk /dev/(device identifier)’
# Run ‘pvscan’ to make sure you can see the new physical volume
# Run ‘pvcreate /dev/(device)’ to create the partition
# Use vgextend to add the new hard disk to the volume group (eg vgextend vg0 /dev/sdb1)
# Unmount the LVM (eg umount /dev/vg0)
# Extend the volume groups using lvextend for each machine (eg lvextend -L+10GB /dev/vg0/maze)
# Check the file systems using e2fsck (eg e2fsck -f /dev/vg0/maze)
# Resize the partition using resize2fs (eg resize2fs /dev/vg0/sorb-disk)
# Remount the volume group (eg mount /dev/vg0)
# pvcreate /dev/(device)
# vgextend vg0 /dev/(device)
- __Mount lvm partitions__
- Create mapping
kpartx -a /dev/VolGroup01/hardy1-disk
- Device /dev/mapper/hardy1-disk1 will be created
- Delete mapping
kpartx -d /dev/VolGroup01/hardy1-disk Create an LVM snapshot
lvcreate -L 1G -s -n $SNAPSHOT $VMDISK
- dd snapshot to a file
dd if=$SNAPSHOT 2>/dev/null|gzip > $BACKUPFILE
- Restore the lvm from the file
gunzip -c snapshot.img.gz|dd of=/dev/vg0/destination-disk
- Copy and restore with dd over ssh
dd if=/dev/vg0/source-lvm-disk | pv| gzip | ssh root@ 'gunzip | dd of=/dev/vg0/destination-lvm-disk'
OR
ssh root@destination 'dd if=/dev/vg0/source-lvm-disk | gzip' | gunzip | dd of=/dev/vg0/destination-lvm-disk
- __Merge Snapshots__
- Take snapshot
lvcreate -L 5G -s -n $SNAPSHOT $VMDISK
- Restore back from the snapshot
lvconvert --merge $SNAPSHOT
- __fix broken VG__
- Run, to determine which device is missing
vgdisplay --partial --verbose multipath -ll
- Determine the latest lvm archive log
ls -latr /etc/lvm/archive/
- Recreate the metadata for missing disk
pvcreate --uuid "XUo7SJ-mbie-vMfI-9dqd-gaLf-UYp9-Jawvl7" --restorefile /etc/lvm/archive/vg0_00085.vg /dev/mapper/mpath3
- Restart the lvm
/etc/init.d/lvm restart