ceph/doc/dev/ceph-volume/zfs.rst

   1
   2 .. _ceph-volume-zfs-api:
   3
   4 ZFS
   5 ===
   6 The backend of ``ceph-volume zfs`` is ZFS, it relies heavily on the usage of
   7 tags, which is a way for ZFS to allow extending its volume metadata. These
   8 values can later be queried against devices and it is how they get discovered
   9 later.
  10
  11 Currently this interface is only usable when running on FreeBSD.
  12
  13 .. warning:: These APIs are not meant to be public, but are documented so that
  14              it is clear what the tool is doing behind the scenes. Do not alter
  15              any of these values.
  16
  17
  18 .. _ceph-volume-zfs-tag-api:
  19
  20 Tag API
  21 -------
  22 The process of identifying filesystems, volumes and pools as part of Ceph relies
  23 on applying tags on all volumes. It follows a naming convention for the
  24 namespace that looks like::
  25
  26     ceph.<tag name>=<tag value>
  27
  28 All tags are prefixed by the ``ceph`` keyword to claim ownership of that
  29 namespace and make it easily identifiable. This is how the OSD ID would be used
  30 in the context of zfs tags::
  31
  32     ceph.osd_id=0
  33
  34 Tags on filesystems are stored as property.
  35 Tags on a zpool are stored in the comment property as a concatenated list
  36 seperated by ``;``
  37
  38 .. _ceph-volume-zfs-tags:
  39
  40 Metadata
  41 --------
  42 The following describes all the metadata from Ceph OSDs that is stored on a
  43 ZFS filesystem, volume, pool:
  44
  45
  46 ``type``
  47 --------
  48 Describes if the device is an OSD or Journal, with the ability to expand to
  49 other types when supported
  50
  51 Example::
  52
  53     ceph.type=osd
  54
  55
  56 ``cluster_fsid``
  57 ----------------
  58 Example::
  59
  60     ceph.cluster_fsid=7146B649-AE00-4157-9F5D-1DBFF1D52C26
  61
  62
  63 ``data_device``
  64 ---------------
  65 Example::
  66
  67     ceph.data_device=/dev/ceph/data-0
  68
  69
  70 ``data_uuid``
  71 -------------
  72 Example::
  73
  74     ceph.data_uuid=B76418EB-0024-401C-8955-AE6919D45CC3
  75
  76
  77 ``journal_device``
  78 ------------------
  79 Example::
  80
  81     ceph.journal_device=/dev/ceph/journal-0
  82
  83
  84 ``journal_uuid``
  85 ----------------
  86 Example::
  87
  88     ceph.journal_uuid=2070E121-C544-4F40-9571-0B7F35C6CB2B
  89
  90
  91 ``osd_fsid``
  92 ------------
  93 Example::
  94
  95     ceph.osd_fsid=88ab9018-f84b-4d62-90b4-ce7c076728ff
  96
  97
  98 ``osd_id``
  99 ----------
 100 Example::
 101
 102     ceph.osd_id=1
 103
 104
 105 ``block_device``
 106 ----------------
 107 Just used on :term:`bluestore` backends. Captures the path to the logical
 108 volume path.
 109
 110 Example::
 111
 112     ceph.block_device=/dev/gpt/block-0
 113
 114
 115 ``block_uuid``
 116 --------------
 117 Just used on :term:`bluestore` backends. Captures either the logical volume UUID or
 118 the partition UUID.
 119
 120 Example::
 121
 122     ceph.block_uuid=E5F041BB-AAD4-48A8-B3BF-31F7AFD7D73E
 123
 124
 125 ``db_device``
 126 -------------
 127 Just used on :term:`bluestore` backends. Captures the path to the logical
 128 volume path.
 129
 130 Example::
 131
 132     ceph.db_device=/dev/gpt/db-0
 133
 134
 135 ``db_uuid``
 136 -----------
 137 Just used on :term:`bluestore` backends. Captures either the logical volume UUID or
 138 the partition UUID.
 139
 140 Example::
 141
 142     ceph.db_uuid=F9D02CF1-31AB-4910-90A3-6A6302375525
 143
 144
 145 ``wal_device``
 146 --------------
 147 Just used on :term:`bluestore` backends. Captures the path to the logical
 148 volume path.
 149
 150 Example::
 151
 152     ceph.wal_device=/dev/gpt/wal-0
 153
 154
 155 ``wal_uuid``
 156 ------------
 157 Just used on :term:`bluestore` backends. Captures either the logical volume UUID or
 158 the partition UUID.
 159
 160 Example::
 161
 162     ceph.wal_uuid=A58D1C68-0D6E-4CB3-8E99-B261AD47CC39
 163
 164
 165 ``compression``
 166 ---------------
 167 A compression-enabled device can allways be set using the native zfs settings on
 168 a volume or filesystem. This will/can be activated during creation of the volume
 169 of filesystem.
 170 When activated by ``ceph-volume zfs`` this tag will be created.
 171 Compression manually set AFTER ``ceph-volume`` will go unnoticed, unless this
 172 tag is also manually set.
 173
 174 Example for an enabled compression device::
 175
 176     ceph.vdo=1