Mount persistent memory (PMEM)

1. Install virtual machine (bridge network mode)

1. Select [typical (recommended)] to proceed to the next step
   

2. Select the installation operation later and click next
   

3. Select [client operating system - Linux, version CentOS 7 64 bit], next
   

4. Virtual machine naming, next step
   

5. [maximum disk size - 60G, split the virtual disk into multiple files] (note that the disk size is not easy to be too small for kernel experiments)
   

6. [custom hardware]
   

7. [memory - 4GB]
   

8. [number of processors - 2, number of cores - 2], check [virtualization Intel VT-x/EPT or AMD-V/RVI]
   

9. Use the ISO image file to locate the downloaded ISO file of CentOS
   

10. Network adapter select bridge mode
    

11. Click close to finish the final configuration preview, and click finish
    

12. Start the virtual machine and click enter
    

13. Select Chinese for configuration text
    

14. Configure [software selection], select [server with GUI], and [finish] in the upper left corner
    

15. Configuration [installation location]
    

16. Select [I want to configure partition] and [finish] in the upper left corner
    

17. Select [standard partition] and click [+] to add the mount point (note that the experiment of compiling the kernel should not add too small memory to / boot)
    
    
    

18. Finish, accept changes
    

19. Start installation (set root password, create user)
    

20. Configure bridge network

    1. Configuration Bridge

       vi /etc/sysconfig/network-scripts/ifcfg-cloudbr0
       

       Insert:

       #[ifcfg-cloudbr0], there was no such file originally
       DEVICE=cloudbr0
       TYPE=Bridge
       ONBOOT=yes
       BOOTPROTO=static
       IPV6INIT=no
       IPV6_AUTOCONF=no
       DELAY=5
       IPADDR=192.168.1.2[Of the same network segment as the host ip Address]
       GATEWAY=192.168.1.1[gateway xxx.xxx.xxx.1]
       NETMASK=255.255.255.0
       DNS1=8.8.8.8
       DNS2=8.8.4.4
       STP=yes
       USERCTL=no
       NM_CONTROLLED=no
       # Remember to delete these comments
       

    2. Modify network configuration

       vi /etc/sysconfig/network-scripts/ifcfg-ens33.
       

       Amend to read:

       TYPE=Ethernet
       PROXY_METHOD=none
       BROWSER_ONLY=no
       BOOTPROTO=none
       DEFROUTE=yes
       IPV4_FAILURE_FATAL=no
       IPV6INIT=no
       IPV6_AUTOCONF=no
       IPV6_DEFROUTE=no
       IPV6_FAILURE_FATAL=no
       IPV6_ADDR_GEN_MODE=stable-privacy
       NAME=ens33
       UUID=522f2028-1e48-421b-9c25-aef00237719d
       DEVICE=ens33
       ONBOOT=yes
       BRIDGE=cloudbr0
       

    3. Restart the network

       chkconfig network on
       systemctl stop NetworkManager
       systemctl disable NetworkManager
       systemctl restart network
       

##2. Compile kernel enable PMEM module

1. Download kernel

   The kernel can be downloaded through the official Linux website or through some domestic websites.

   Recommended kernel version: linux-4.16.10

   Compressed package after downloading: linux-4.16.10 tar. gz

2. Unzip (unzip the compressed package to / usr/src directory)

   tar xf linux-4.16.10.tar.gz -C /usr/src
   

3. Configure kernel

   cd linux-4.16.10
   

   Enter the extracted kernel version directory and execute the following command

   make menuconfig
   

   Note that some packages need to be installed before the command is executed (if a package is still missing, just install it according to the prompt)

   yum install gcc
   yum install ncurses ncurses-devel
   

   To enter the graphical configuration interface, you need to be able to PMEM module

   -> Device Drivers -> NVDIMM Support ->
   <M>PMEM; <M>BLK; <*>BTT
   //Adjust by space
   

   //Back to the home page
   -> Processor type and features
   <*>Support non-standard NVDIMMs and ADR protected memory
   

4. Compile kernel

   make -j4
   //j4 means that four compilation commands are executed at the same time. j8 can be used on 4-core machines
   //Similarly, if any package is missing, install it according to the prompt
   

5. Compiling and installing modules

   make modules
   make modules_install
   

6. Modify grub file

   nano /etc/default/grub  
   

   Add as follows:

   memmap=nn[KMG]!ss[KMG] 
   #Allocate the memory area as PMEM, ss represents the starting memory address, and nn represents the area size, such as 4G!12G represents the memory range from 12G to 16G as PMEM [KMG] indicates KB,MB,GB The details are as follows:
   GRUB_CMDLINE_LINUX="memmap=4G!4G"
   

7. Update grub file

   //CentOS instruction
   grub2-mkconfig -o /boot/grub2/grub.cfg
   //If the user is ubuntu
   update-grub2
   

8. Restart the virtual machine

   reboot
   

   Select the corresponding compiled kernel system
   After restart, check the drive directory dev to see that PEME0 has been successfully mounted

   ls /dev
   

   Mount succeeded

3. Configure the persistent memory as a local disk

1. Install persistent memory management tools

   yum install -y ndctl daxctl
   

2. The configuration usage mode is fsdax

   ndctl create-namespace -f -e namespace0.0 --mode=fsdax
   

3. Format and mount the disk

   mkfs -t ext4 /dev/pmem0 
   mount -o dax,noatime /dev/pmem0 /mnt
   

4. View mounted disks

   df -h
   

   Configuration succeeded
   

5. be careful
   Note that after the virtual machine is mounted, the mount information will be lost every time the virtual machine is shut down, and it needs to be mounted again after restart.