== Random LVM stuff ==

=== LV caching ===

We use LV caching at least on godard.d.o and smit.d.o. Here are the setup instructions:

* Make sure that both the HDD and SSD are in the same volume group.

* Make sure module loading is enabled

* Run the following command to enable LV caching for the srv LV in the vg0 VG, assuming the SSD is /dev/sda3:

{{{
  lvcreate --type cache --cachemode writethrough -L 120G -n srv_cachepool vg0/srv /dev/sda3
}}}

* It is currently not possible to resize a LV with a LVM cache. The workaround is to disable LV caching, resize the LV and reenable it. LV caching can be disabled with the following command:

{{{
  lvconvert --uncache vg0/srv
}}}