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Diffstat (limited to 'docs/system/deprecated.rst')
| -rw-r--r-- | docs/system/deprecated.rst | 37 |
1 files changed, 20 insertions, 17 deletions
diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst index 728233a8ff..843ae71fc6 100644 --- a/docs/system/deprecated.rst +++ b/docs/system/deprecated.rst @@ -95,23 +95,6 @@ error in the future. The ``-realtime mlock=on|off`` argument has been replaced by the ``-overcommit mem-lock=on|off`` argument. -``-numa node,mem=``\ *size* (since 4.1) -''''''''''''''''''''''''''''''''''''''' - -The parameter ``mem`` of ``-numa node`` is used to assign a part of -guest RAM to a NUMA node. But when using it, it's impossible to manage specified -RAM chunk on the host side (like bind it to a host node, setting bind policy, ...), -so guest end-ups with the fake NUMA configuration with suboptiomal performance. -However since 2014 there is an alternative way to assign RAM to a NUMA node -using parameter ``memdev``, which does the same as ``mem`` and adds -means to actualy manage node RAM on the host side. Use parameter ``memdev`` -with *memory-backend-ram* backend as an replacement for parameter ``mem`` -to achieve the same fake NUMA effect or a properly configured -*memory-backend-file* backend to actually benefit from NUMA configuration. -In future new machine versions will not accept the option but it will still -work with old machine types. User can check QAPI schema to see if the legacy -option is supported by looking at MachineInfo::numa-mem-supported property. - ``-numa`` node (without memory specified) (since 4.1) ''''''''''''''''''''''''''''''''''''''''''''''''''''' @@ -553,3 +536,23 @@ long starting at 1MiB, the old command:: can be rewritten as:: qemu-nbd -t --image-opts driver=raw,offset=1M,size=100M,file.driver=qcow2,file.file.driver=file,file.file.filename=file.qcow2 + +Command line options +-------------------- + +``-numa node,mem=``\ *size* (removed in 5.1) +'''''''''''''''''''''''''''''''''''''''''''' + +The parameter ``mem`` of ``-numa node`` was used to assign a part of +guest RAM to a NUMA node. But when using it, it's impossible to manage a specified +RAM chunk on the host side (like bind it to a host node, setting bind policy, ...), +so the guest ends up with the fake NUMA configuration with suboptiomal performance. +However since 2014 there is an alternative way to assign RAM to a NUMA node +using parameter ``memdev``, which does the same as ``mem`` and adds +means to actually manage node RAM on the host side. Use parameter ``memdev`` +with *memory-backend-ram* backend as replacement for parameter ``mem`` +to achieve the same fake NUMA effect or a properly configured +*memory-backend-file* backend to actually benefit from NUMA configuration. +New machine versions (since 5.1) will not accept the option but it will still +work with old machine types. User can check the QAPI schema to see if the legacy +option is supported by looking at MachineInfo::numa-mem-supported property. |