lvm2 docker direct-lvm setup

gistfile1.txt

VMTHIN(7)                                                                                                  LVMTHIN(7)

NAME
       lvmthin — LVM thin provisioning

Thin Terms
       ThinDataLV
              thin data LV
              large LV created in a VG
              used by thin pool to store ThinLV blocks

       ThinMetaLV
              thin metadata LV
              small LV created in a VG
              used by thin pool to track data block usage

Thin Usage
       The primary method for using lvm thin provisioning:

   1. create ThinDataLV
       Create an LV that will hold thin pool data.

       lvcreate -n ThinDataLV -L LargeSize VG

       Example
       # lvcreate -n pool0 -L 10G vg

   2. create ThinMetaLV
       Create an LV that will hold thin pool metadata.

       lvcreate -n ThinMetaLV -L SmallSize VG
      Example
       # lvcreate -n pool0meta -L 1G vg

       # lvs
         LV        VG Attr       LSize
         pool0     vg -wi-a----- 10.00g
         pool0meta vg -wi-a----- 1.00g


   3. create ThinPoolLV
       Combine the data and metadata LVs into a thin pool LV.
       ThinDataLV is renamed to hidden ThinPoolLV_tdata.
       ThinMetaLV is renamed to hidden ThinPoolLV_tmeta.
       The new ThinPoolLV takes the previous name of ThinDataLV.

       lvconvert --type thin-pool --poolmetadata VG/ThinMetaLV VG/ThinDataLV

       Example
       # lvconvert --type thin-pool --poolmetadata vg/pool0meta vg/pool0

       # lvs vg/pool0
         LV    VG Attr       LSize  Pool Origin Data% Meta%
         pool0 vg twi-a-tz-- 10.00g      0.00   0.00

       # lvs -a
         LV            VG Attr       LSize
         pool0         vg twi-a-tz-- 10.00g
         [pool0_tdata] vg Twi-ao---- 10.00g
         [pool0_tmeta] vg ewi-ao---- 1.00g

Docker:

*  `dm.thinpooldev`

    Specifies a custom blockdevice to use for the thin pool.

    If using a block device for device mapper storage, ideally lvm2
    would be used to create/manage the thin-pool volume that is then
    handed to docker to exclusively create/manage the thin and thin
    snapshot volumes needed for it's containers.  Managing the thin-pool
    outside of docker makes for the most feature-rich method of having
    docker utilize device mapper thin provisioning as the backing
    storage for docker's containers.  lvm2-based thin-pool management
    feature highlights include: automatic or interactive thin-pool
    resize support, dynamically change thin-pool features, automatic
    thinp metadata checking when lvm2 activates the thin-pool, etc.

    Example use:

    ``docker -d --storage-opt dm.thinpooldev=/dev/mapper/thin-pool``

edit /etc/docker.conf

DOCKER_OPTS="-d -p /var/run/docker.pid --storage-opt dm.basesize=50G --storage-opt dm.datadev=/dev/data/data --storage-opt dm.metadatadev=/dev/data/metadata"

change to:

DOCKER_OPTS="-d -p /var/run/docker.pid --storage-opt dm.basesize=50G dm.thinpooldev=/dev/mapper/thin-pool"

Can you please suggest the DR strategy using the direct-LVM apprach? How do I take backup then use rsync to send those backups to a DR site. In another words, how do I take a snapshot in direct-LVM and then do a tar cvf command (or similar) to do an online copy.

Thanks for your inputs.