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authorWei Yang <richardw.yang@linux.intel.com>2019-08-01 08:40:53 +0800
committerMichael S. Tsirkin <mst@redhat.com>2019-09-16 06:27:35 -0400
commitd8b92bd41822c053daa4dbf88cf36b14241a0279 (patch)
treec1a85f072e84ce7bbec1d366d7a8d5f196bd6e17
parent2501db70b24255ebe6503a66a5357377bcbc12c6 (diff)
docs/nvdimm: add example on persistent backend setup
Persistent backend setup requires some knowledge about nvdimm and ndctl tool. Some users report they may struggle to gather these knowledge and have difficulty to setup it properly. Here we provide two examples for persistent backend and gives the link to ndctl. By doing so, user could try it directly and do more investigation on persistent backend setup with ndctl. Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Reviewed-by: Pankaj Gupta <pagupta@redhat.com> Message-Id: <20190801004053.7021-1-richardw.yang@linux.intel.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
-rw-r--r--docs/nvdimm.txt31
1 files changed, 31 insertions, 0 deletions
diff --git a/docs/nvdimm.txt b/docs/nvdimm.txt
index b531cacd35..362e99109e 100644
--- a/docs/nvdimm.txt
+++ b/docs/nvdimm.txt
@@ -171,6 +171,35 @@ guest software that this vNVDIMM device contains a region that cannot
accept persistent writes. In result, for example, the guest Linux
NVDIMM driver, marks such vNVDIMM device as read-only.
+Backend File Setup Example
+--------------------------
+
+Here are two examples showing how to setup these persistent backends on
+linux using the tool ndctl [3].
+
+A. DAX device
+
+Use the following command to set up /dev/dax0.0 so that the entirety of
+namespace0.0 can be exposed as an emulated NVDIMM to the guest:
+
+ ndctl create-namespace -f -e namespace0.0 -m devdax
+
+The /dev/dax0.0 could be used directly in "mem-path" option.
+
+B. DAX file
+
+Individual files on a DAX host file system can be exposed as emulated
+NVDIMMS. First an fsdax block device is created, partitioned, and then
+mounted with the "dax" mount option:
+
+ ndctl create-namespace -f -e namespace0.0 -m fsdax
+ (partition /dev/pmem0 with name pmem0p1)
+ mount -o dax /dev/pmem0p1 /mnt
+ (create or copy a disk image file with qemu-img(1), cp(1), or dd(1)
+ in /mnt)
+
+Then the new file in /mnt could be used in "mem-path" option.
+
NVDIMM Persistence
------------------
@@ -212,3 +241,5 @@ References
https://www.snia.org/sites/default/files/technical_work/final/NVMProgrammingModel_v1.2.pdf
[2] Persistent Memory Development Kit (PMDK), formerly known as NVML project, home page:
http://pmem.io/pmdk/
+[3] ndctl-create-namespace - provision or reconfigure a namespace
+ http://pmem.io/ndctl/ndctl-create-namespace.html