diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/interop/nbd.txt | 23 | ||||
| -rw-r--r-- | docs/system/deprecated.rst | 3 | ||||
| -rw-r--r-- | docs/tools/qemu-nbd.rst | 8 |
3 files changed, 27 insertions, 7 deletions
diff --git a/docs/interop/nbd.txt b/docs/interop/nbd.txt index f3b3cacc96..10ce098a29 100644 --- a/docs/interop/nbd.txt +++ b/docs/interop/nbd.txt @@ -17,19 +17,31 @@ namespace "qemu". == "qemu" namespace == -The "qemu" namespace currently contains only one type of context, -related to exposing the contents of a dirty bitmap alongside the -associated disk contents. That context has the following form: +The "qemu" namespace currently contains two available metadata context +types. The first is related to exposing the contents of a dirty +bitmap alongside the associated disk contents. That metadata context +is named with the following form: qemu:dirty-bitmap:<dirty-bitmap-export-name> Each dirty-bitmap metadata context defines only one flag for extents in reply for NBD_CMD_BLOCK_STATUS: - bit 0: NBD_STATE_DIRTY, means that the extent is "dirty" + bit 0: NBD_STATE_DIRTY, set when the extent is "dirty" + +The second is related to exposing the source of various extents within +the image, with a single metadata context named: + + qemu:allocation-depth + +In the allocation depth context, the entire 32-bit value represents a +depth of which layer in a thin-provisioned backing chain provided the +data (0 for unallocated, 1 for the active layer, 2 for the first +backing layer, and so forth). For NBD_OPT_LIST_META_CONTEXT the following queries are supported -in addition to "qemu:dirty-bitmap:<dirty-bitmap-export-name>": +in addition to the specific "qemu:allocation-depth" and +"qemu:dirty-bitmap:<dirty-bitmap-export-name>": * "qemu:" - returns list of all available metadata contexts in the namespace. @@ -55,3 +67,4 @@ the operation of that feature. NBD_CMD_BLOCK_STATUS for "qemu:dirty-bitmap:", NBD_CMD_CACHE * 4.2: NBD_FLAG_CAN_MULTI_CONN for shareable read-only exports, NBD_CMD_FLAG_FAST_ZERO +* 5.2: NBD_CMD_BLOCK_STATUS for "qemu:allocation-depth" diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst index 0ebce37a19..32a0e620db 100644 --- a/docs/system/deprecated.rst +++ b/docs/system/deprecated.rst @@ -257,7 +257,8 @@ the 'wait' field, which is only applicable to sockets in server mode '''''''''''''''''''''''''''''''''''''''''''''''''''''''' Use the more generic commands ``block-export-add`` and ``block-export-del`` -instead. +instead. As part of this deprecation, where ``nbd-server-add`` used a +single ``bitmap``, the new ``block-export-add`` uses a list of ``bitmaps``. Human Monitor Protocol (HMP) commands ------------------------------------- diff --git a/docs/tools/qemu-nbd.rst b/docs/tools/qemu-nbd.rst index 667861cb22..fe41336dc5 100644 --- a/docs/tools/qemu-nbd.rst +++ b/docs/tools/qemu-nbd.rst @@ -72,10 +72,16 @@ driver options if ``--image-opts`` is specified. Export the disk as read-only. +.. option:: -A, --allocation-depth + + Expose allocation depth information via the + ``qemu:allocation-depth`` metadata context accessible through + NBD_OPT_SET_META_CONTEXT. + .. option:: -B, --bitmap=NAME If *filename* has a qcow2 persistent bitmap *NAME*, expose - that bitmap via the ``qemu:dirty-bitmap:NAME`` context + that bitmap via the ``qemu:dirty-bitmap:NAME`` metadata context accessible through NBD_OPT_SET_META_CONTEXT. .. option:: -s, --snapshot |