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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
commit | e6918187568dbd01842d8d1d2c808ce16a894239 (patch) | |
tree | 64f88b554b444a49f656b6c656111a145cbbaa28 /doc/dev/ceph-volume/zfs.rst | |
parent | Initial commit. (diff) | |
download | ceph-e6918187568dbd01842d8d1d2c808ce16a894239.tar.xz ceph-e6918187568dbd01842d8d1d2c808ce16a894239.zip |
Adding upstream version 18.2.2.upstream/18.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | doc/dev/ceph-volume/zfs.rst | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/doc/dev/ceph-volume/zfs.rst b/doc/dev/ceph-volume/zfs.rst new file mode 100644 index 000000000..18de7652a --- /dev/null +++ b/doc/dev/ceph-volume/zfs.rst @@ -0,0 +1,176 @@ + +.. _ceph-volume-zfs-api: + +ZFS +=== +The backend of ``ceph-volume zfs`` is ZFS, it relies heavily on the usage of +tags, which is a way for ZFS to allow extending its volume metadata. These +values can later be queried against devices and it is how they get discovered +later. + +Currently this interface is only usable when running on FreeBSD. + +.. warning:: These APIs are not meant to be public, but are documented so that + it is clear what the tool is doing behind the scenes. Do not alter + any of these values. + + +.. _ceph-volume-zfs-tag-api: + +Tag API +------- +The process of identifying filesystems, volumes and pools as part of Ceph relies +on applying tags on all volumes. It follows a naming convention for the +namespace that looks like:: + + ceph.<tag name>=<tag value> + +All tags are prefixed by the ``ceph`` keyword to claim ownership of that +namespace and make it easily identifiable. This is how the OSD ID would be used +in the context of zfs tags:: + + ceph.osd_id=0 + +Tags on filesystems are stored as property. +Tags on a zpool are stored in the comment property as a concatenated list +separated by ``;`` + +.. _ceph-volume-zfs-tags: + +Metadata +-------- +The following describes all the metadata from Ceph OSDs that is stored on a +ZFS filesystem, volume, pool: + + +``type`` +-------- +Describes if the device is an OSD or Journal, with the ability to expand to +other types when supported + +Example:: + + ceph.type=osd + + +``cluster_fsid`` +---------------- +Example:: + + ceph.cluster_fsid=7146B649-AE00-4157-9F5D-1DBFF1D52C26 + + +``data_device`` +--------------- +Example:: + + ceph.data_device=/dev/ceph/data-0 + + +``data_uuid`` +------------- +Example:: + + ceph.data_uuid=B76418EB-0024-401C-8955-AE6919D45CC3 + + +``journal_device`` +------------------ +Example:: + + ceph.journal_device=/dev/ceph/journal-0 + + +``journal_uuid`` +---------------- +Example:: + + ceph.journal_uuid=2070E121-C544-4F40-9571-0B7F35C6CB2B + + +``osd_fsid`` +------------ +Example:: + + ceph.osd_fsid=88ab9018-f84b-4d62-90b4-ce7c076728ff + + +``osd_id`` +---------- +Example:: + + ceph.osd_id=1 + + +``block_device`` +---------------- +Just used on :term:`bluestore` backends. Captures the path to the logical +volume path. + +Example:: + + ceph.block_device=/dev/gpt/block-0 + + +``block_uuid`` +-------------- +Just used on :term:`bluestore` backends. Captures either the logical volume UUID or +the partition UUID. + +Example:: + + ceph.block_uuid=E5F041BB-AAD4-48A8-B3BF-31F7AFD7D73E + + +``db_device`` +------------- +Just used on :term:`bluestore` backends. Captures the path to the logical +volume path. + +Example:: + + ceph.db_device=/dev/gpt/db-0 + + +``db_uuid`` +----------- +Just used on :term:`bluestore` backends. Captures either the logical volume UUID or +the partition UUID. + +Example:: + + ceph.db_uuid=F9D02CF1-31AB-4910-90A3-6A6302375525 + + +``wal_device`` +-------------- +Just used on :term:`bluestore` backends. Captures the path to the logical +volume path. + +Example:: + + ceph.wal_device=/dev/gpt/wal-0 + + +``wal_uuid`` +------------ +Just used on :term:`bluestore` backends. Captures either the logical volume UUID or +the partition UUID. + +Example:: + + ceph.wal_uuid=A58D1C68-0D6E-4CB3-8E99-B261AD47CC39 + + +``compression`` +--------------- +A compression-enabled device can always be set using the native zfs settings on +a volume or filesystem. This will/can be activated during creation of the volume +of filesystem. +When activated by ``ceph-volume zfs`` this tag will be created. +Compression manually set AFTER ``ceph-volume`` will go unnoticed, unless this +tag is also manually set. + +Example for an enabled compression device:: + + ceph.vdo=1 |