LVM cache contd: Tip: Using tags

(Thanks Alasdair Kergon)

# pvchange --addtag ssd /dev/sdc1
  Physical volume "/dev/sdc1" changed
  1 physical volume changed / 0 physical volumes not changed
# pvchange --addtag slow /dev/md127
  Physical volume "/dev/md127" changed
  1 physical volume changed / 0 physical volumes not changed
# pvs -o+tags
  PV         VG        Fmt  Attr PSize   PFree   PV Tags
  /dev/md127 vg_guests lvm2 a--    1.82t 962.89g slow
  /dev/sdc1  vg_guests lvm2 a--  232.88g 232.88g ssd

These tags can be used when placing logical volumes on to specific physical volumes:

# lvcreate -L 800G -n testorigin vg_guests @slow

1. https://www.redhat.com/archives/linux-lvm/2014-May/msg00047.html
2. https://www.redhat.com/archives/linux-lvm/2014-May/msg00048.html