Hi, Stefan Thanks for your comments :-)
On Mon, Jul 29, 2019 at 02:58:59PM +0100, Stefan Hajnoczi wrote: >On Wed, Jul 24, 2019 at 03:03:07PM +0800, Wei Yang wrote: >> 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.y...@linux.intel.com> >> --- >> docs/nvdimm.txt | 28 ++++++++++++++++++++++++++++ >> 1 file changed, 28 insertions(+) >> >> diff --git a/docs/nvdimm.txt b/docs/nvdimm.txt >> index b531cacd35..baba7a940d 100644 >> --- a/docs/nvdimm.txt >> +++ b/docs/nvdimm.txt >> @@ -171,6 +171,32 @@ 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 I use '-' because I want to say this is a sub-section of "Guest Data Persistence". Actually, I struggled a little to pick up a proper character. Do you think '-' is the proper one? > >For consistency with the rest of the document please use '-' instead of >'.'. > >> + >> +Here is two examples for how to setup these persistent backend on >> +linux, which leverages the tool ndctl [3]. > >Small grammar tweaks: > > Here are two examples showing how to set up persistent backends on > Linux using the tool ndctl [3]. > >> + >> +It is easy to setup DAX device backend file. > >Please move this into the "A. DAX device" section and use it as an >introduction to explain what this section is about: > > 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: > >> + >> +A. DAX device >> + >> + ndctl create-namespace -f -e namespace0.0 -m devdax >> + >> +The /dev/dax0.0 could be used directly in "mem-path" option. >> + >> +For DAX file, it is more than creating the proper namespace. The >> +block device should be partitioned and mounted (with dax option). > >Please move this into "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: > >> + >> +B. DAX file >> + >> + ndctl create-namespace -f -e namespace0.0 -m fsdax >> + (partition /dev/pmem0 with name pmem0p1) >> + mount -o dax /dev/pmem0p1 /mnt >> + (dd a file with proper size in /mnt) > >"dd a file" could be "create or copy a disk image file with qemu-img(1), >cp(1), or dd(1) in /mnt". -- Wei Yang Help you, Help me
